Payout Request Timing Question: When is it safe to continue trading the account?

I've been doing some searching and reading, but it's not clear to me yet.

I understand that if I use ACH, it can take 1-3 business days to get the funds in my bank account.

But at what point is it ok for me to continue trading the XFA? Is it when the XFA shows the adjusted account balance even when the funds haven't arrived?

I haven't taken a payout yet, but I'm close so I was wondering. I'd hate to request a payout then blow the account before the payout goes through or something like that.

Thanks!