I'm confused with what you just said, you need to understand what discretionary funds means money kept aside for your own discretion and this can only be done after all of your bills have been accounted for so the money set aside for emergencies come from your discretionary funds, you can only save from what's left after all necessary bills and payments have been settled and this money that's left is your discretionary funds and it is from this money that you save from for emergencies.
Your emergency fund isn't different from your discretionary fund, it is a part of it, so a part of your discretionary funds can go into bitcoin investment and another part can be saved for emergencies that may come up.
I think it is more about the technicalities of managing the funds that we have because when someone wants to become an investor by buying Bitcoin, of course he himself has already considered his capital and he knows where the capital comes from so when he wants to manage the flow of funds where he wants to take it, he already knows before he does it. Because problems like bills are not the same for everyone, so the amount of funds allocated to be able to buy Bitcoin from the routine funds generated can also vary from person to person. So I think it's more about the small ways or techniques of working without having to sacrifice one of the important aspects of life. Like staying healthy and not being hungry just because of investment.