...
If you are interested in the formula so you can calculate it for all situations:
credit_satoshi_price = ((1 / usd_credit_rate) / btc_usd_price) * 100000000
....
With the BTC price at $1000 then we'd get 1 credit = 0.8333333333.
With the BTC price at $5000 then we'd get 1 credit = 0.1666666667.
And with the BTC price at $20,000 then we'd get 1 credit = 0.04166666667.
As you can see it's almost impossible (with our current times) for the 50k limit to make withdrawing "impossible". For it to become impossible (when you withdraw 50k credits and get 1 or less satoshi) the BTC price would need to be $40,000,000 per bitcoin.
mex, why did you halve everything? here are some your words. so these conditions ceased. in this your post it seems you are ok also with price $5000. Today is price about $4300 and you halved everything. can you explain us why it was ok before and now not? thank you
by the way, i will play virtual pub cause i like this game.

but i am curious about what have been done.