I think it is best to create wallet that has function to sign message and prove ownership on desktop computer or laptop.
I think we can create two wallets.
One for important ownership and serious deal.
One for less important thing.
The first wallet should be created on desktop computer or laptop.
The second wallet should be created on mobile for convenience.
What wallet supports signing message on mobile?
It is good if it supports Legacy, Nested Segwit, Native Segwit and perfect if support Taproot too. If a wallet supports Legacy, Nested and Native Segwit to sign message, it is perfect. I do not find a wallet that support signing message from Taproot address.
I think for wallet for ownership, I will not store my Bitcoin in it. Especially the wallet on mobile.
Any wallet with any serious amounts should never be created on a laptop or desktop or phone but on a separate hardware device.
I think the number I times I have wanted to / had to sign something with an address on my mobile wallet over the last 8 years or so can be counted on the fingers of one hand.
There are a few that do some signing of certain types, none that do all, and as far as I know none that do taproot.
-Dave