The only challenge that someone using DCA method is when the source of income is not steady
This was my thinking too and I even made a comment referencing an entrepreneur. Thankfully, JJG explained convincingly, how this can be achieved. From that explanation, you can actually know your financial inflow within a certain period like a year, from that you can know what to set aside and plan your DCA accordingly. You must not be earning fixed income monthly or weakly before you can perform DCA, even when your inflow is not regular, you can take average with a time period and as soon as you have any bulk funds, you can start off with the part that fits into the average you have worked out already and because it is exhausted, you would have receieved another inflow base on your calculations.
I like to think about the non-steady income in a couple of parts.
The first part is just figuring out what is your worst-case scenarios, what are your best case scenarios and what is your average... So then with that information you can try to project ahead, and most likely mostly using some combination of the worst-case scenarios and the average in order to figure out how much money you need to keep in your emergency fund in order to cover those situations in which the worst-case scenarios ended up playing out rather than the average case scenarios.
So, even though not necessarily likely worst-case scenarios could end up playing out for 6-12 months or more, and so the emergency cash fund should be able to cover the gap between what you need to live and what kind of income is coming in. Hopefully, you are already spending (your monthly expenses) somewhere less than your average case scenario which should then cause for an ability to invest (or DCA) with part of the amount that you are living below your average case scenario. and sure if the worse case scenario persists for a long time, you may well end up needing to either reduce or eliminate your DCA purchases of bitcoin, but if you have planned in advance you should not necessarily need to stop your DCA, and for sure, you do not want to end up putting yourself in a position in which you end up having to sell any of your BTC during periods in which worse case scenarios are playing out.. which likely would mean that you had not sufficiently prepared in terms of your emergency fund and/or the ways that you had been choosing to live in order to make sure that you are generally living below the amount of your average case scenarios rather than spending more than that.
JJG, I know that you are an old G bitcoin holder with so much experience and different strategy on how to accumulate bitcoin. I also agree to what you said on how someone that isn't having a steady cash inflow can use his average cash inflow for the year to plan on how much he will use on DCAing or to always have an amount that will be left based on always planning and keeping funds for worst scenario than average case scenario. I wouldn't like to such happen in my own bitcoin journey accumulation, the reason is that I have just started my bitcoin journey and I haven't accumulate a significant amount which I can be proud of. Not having regular cash inflow will be a big challenge to me because it will slow the amount of bitcoin I will accumulate, and I am not even sure of accumulate, unlike the regular cash inflow pattern. This is because you might prepare and plan very well on this, but along the line, it might come to play that your worst scenario expectation came out to be more than what you have planned for, because there are unforeseen challenges that will come to play during this period, which you didn't plan for that must be included because of it is an emergency.
I will use myself as a case study, I plan on how much I spend weekly and let me say if I budgeted $200, I will end up spending up $250 and sometimes $300, but because I have a steady cash inflow I don't feel it. I could remember when I have not gotten job that was frequently paying me, I find it difficult to manage the one that I have worked to use till when another funds comes in, because of this unforeseen circumstances that do occur. I am happy JJG, that you said if you did not make a proper calculation so that your worst case scenario funds should be higher, one might end up falling back to sell his bitcoin due to lack of proper preparation. I am not good at managing a certain amount of funds for some time before another funds comes in because, nobody knows what will happen next, this is why I feel that regular income will help in DCAing better for me. Although, everyone has their own strategy of DCA base on the way they get their income.