I mean, the way here in the first place is to avoid the initial premise of other people knowing that you have a sizeable amount of Bitcoin or heck, money in general. Unless you had some sizeable amount of confidence behind your security then I don't think there's a reason to share about it in the first place.

But considering it did happen, I'd give the money 100%. Nothing's more important than your life after all. If possible and I have enough proof I can even probably try to ask exchanges to mark the coins to be tainted/stolen, only if possible and hey, if lucky, get it back.

I say the content you quoted here's a little bit of a stretch against what OP's trying to suppose but it's still good advice. Personally I'd say it's stupid of the kidnapped to be using a single wallet for all his bitcoins in the first place, When some of the average joes in here are not even comfortable saving their wealths of bitcoin in 2-3 wallets. But we're in here, we can't really get out of the rut unless we spit out the key phrases, and yet I think I'd keep my mouth shut about my passphrase and just let them have their way. 90% of kidnappers kill their victims anyway, so my chances of getting out of there alive is already slim. If I give them an advantage over my family I'm just gonna be dead and my family's gonna be left penniless lol.

I'd carry my passphrases to the death and would not tell a single soul except my future family about it. Heck I wouldn't even tell them about it until I know I'm gonna die cause they might just hasten the whole ordeal for me so they can get inheritance moolah which seems to happen a little more often than most of us think.

It should be safe if a bitcoin holders remains anonymous from the start and does not tell other people that he/she has Bitcoin in their wallet. Because in most cases of kidnapping of Bitcoin holders it starts when they tell other people about how much Bitcoin they have or when they flex what they hold.
Or Bitcoin holders can avoid traveling far away or to places with low security if they are a well-known person whose number of Bitcoins they hold is known to many people, and as often as possible uploads their activities on social media to inform many people regarding their activities. And if possible, bitcoin holders doesn't need to share their private key with other people, even if it's their siblings or parents, to reduce unwanted things.

This is the weak point in any security system, namely "physical violence" and it applies to everything that has value.

You could have Gold coins or cash stashed away somewhere or simply a valueble item that someone wants.... bitcoins are no different than any of these things.

My solution : Split your hoard, so that you can give up, only a portion of your whole hoard and keep quite about your wealth.

I would say:

Sort out your priorities

Life is always dangerous, every second of it. You can have an accident, stumble in the shower and break your neck, or get run over while trying to cross a street. Or maybe get a serious health issue and have pain for the rest of your life.

So your job is to find an individual approach to a risk level you are comfortable with. If you worry about the risk of a plane crash, maybe take the train instead, on the other hand if you enjoy freeclimbing , maybe it is worth the risk for you......

My priorities:

1) Stay alive - if you are dead the rest will not matter
2) Stay healthy - being sick and in pain is not my idea of a good life
3) Try to have some money to pay for nice things..... But money can be easily replaced, not so much with health.....

To sum it up:

Try to reduce unnessary risks as much as possible. If you encounter a risky situation try to achiebe the least worse outcome.

Back to Bitcoin, I think try to keep a low profile and protect your wallet.
If the above is not enough than just accept that you will maybe lose your bitcoins, but on the other hand at least you keep your life and your health and then be happy about this

OP telling you the truth there is no way those kidnappers are going to let live without telling them were you hide your bitcoins.
But OP firstly how did they no you are a bitcoin holder cause it will be to hard for people to find what you are into bitcoin or maybe you did tell a close friend about it and fame you all cause no body is to be trusted you never can tell who the person will be..
So back to your story if I was in shoes I will just give them what they want cause if there is life there is still hope as for me maybe that what I will do in that situation.

First I must tell you that Bitcoin is a Treasury investment that is proefficiently attractive as gold which could whisper betraying, greeds and selfish interests amongst individuals that are interactive or related in a circle in this Bitcoin industry.

@ OP, I can tell you not to trust anyone in this Bitcoin journey not even a Bitcoin colleague as you may say.
Sometimes some persons intellectually grosses around you with a friendly mode but on a diverse motive in disguise surveying to decode possibilities to take advantages of you if possible.

In this Bitcoin space, there are full of envies and traitors so, be sensitive in responding and relating with such persons.
However, your life is more important that the treasures you have accumulated or all that proefficient accountabilities you have laboured in this World that count be compared to your life.

Let go the treasures for your life to stay because there is hope for recovery.

If you look at firearms make sure you get proper training how to use them and practice regularly.  You don't want to get killed by your own gun or maybe kill a todler next door, just because the bullet went through several walls..... and you had no idea how powerful a bullet can be....

There are ways that these people will know that you are a bitcoin holder. If you're someone that keeps on posting some charts or anything related to cryptocurrencies on your social media, then that's the best way that they'll know if someone is into this market and are an investor.
That's the reason if you're posting related to crypto on your social media accounts, it's best to just remain lowkey and keep them private because it's a financial matter that you should keep private.