What would be the possible steps that we should follow for those users (like me) who have BTC Addresses that can't be signed a Message?
Been using Coins.PH for a long time
I think it's time for you to become a real Bitcoin user

Get a wallet that gives you access to your private keys, and don't rely on third parties to hold your Bitcoin.
Then, post a Bitcoin address in
Stake your Bitcoin address here, so you can use it to prove ownership
at the time you post that. An older post is of course better, but if you don't have that yet,
now is the best time to make one.
If you really don't want to create a wallet, get a Bitcoin address from
bitaddress.org: click Paper Wallet, print it, keep your copy safe, and post the address in the thread I mentioned above. If it ever comes to it, you can use it to prove ownership.