Any future plans to be able to permanently lock a BTC payout address?

I can do that easily. Are you a provider?

Locked!

Whoever would like their BTC address to get locked for security reasons, send me PM and I will lock it for you.

what does that mean?

That your payout BTC address cannot be changed (in case someone hacks your account).

But you could change it if we needed to? Should you make that a default, that its locked? Just in case......

No, because some providers would not feel comfortable not being able to change BTC address the moment they want to.