[edited out]
Another thing for me and I think the best approach to accumulation is to allocate 20% to bitcoin, keep 20% as an emergency fund for things that might happen unexpectedly, and the remaining 60% to make ends meet.
Even those kinds of numbers of being able to have 40% discretionary income come off as a bit unrealistic in terms of typical situations that people find themselves in, and you might even be using the term emergency fund wrong, since you seem to be referring to having an extra amount of money as a kind of float in the month to cover unexpected other expenses that might come up. An emergency fund is generally something that is built up and would likely be a minimum of 3 months, and it should hardly ever be touched since the guy should have other funds that are available so that he never has to touch his emergency fund absent an actual emergency.. and so the size and the maintenance of the emergency fund becomes ever more important with any kind of volatile investment such as bitcoin, since we likely should be investing into bitcoin for the long term of 4-10 years or longer, so we don't want to be getting ourselves into any kind of situation in which we have to touch any of our bitcoin during that period for any reason, except our complete own choosing.. and based on various aspects of our investment thesis playing out or BTC levels accumulating to sufficiently high levels that we are moving away from accumulation and into other kinds of stages (practices).
With what you said I think it is still a good idea, and maybe I will make this simpler which is to save 20% of the total income you have every month so that when you feel that you are not enough with the amount of 60% funds for needs because there is something that happens in an emergency such as experiencing illness or any event that requires you to spend some money then you can use the emergency fund without having to interfere with the 20% budget for your bitcoin accumulation which indirectly maintains the consistency of your DCA, but you can also change the percentage if your expenses are more than 60%.