Good to see a new addition on your website.
I have seen the same tool on multiple websites already. I think Bitlist also has it. But thanks for the new tool.
A Cryptographically Relevant Quantum Computer (CRQC) running Shor's algorithm can turn an exposed public key into a private key. When you sign bitcoin messages, you expose the public key.
That's something I wish I'd learned before signing publicly-staked bitcoin address messages (not that you can prevent people from paying to one you never had BTC on to begin with)...
There is no reason to regret it. Creating a new wallet does not cost you anything. You don't need to use the same wallet if you think using it will be a risk for you. I am glad that a Bitcoin wallet is free. I have signed a message from one of my addresses, but that does not mean I will keep my funds in this wallet. I can always choose not to use it anymore. If you are afraid of signing a message using your Bitcoin wallet address, you can always choose PGP instead.