At some point in time when we are depleting so many of our various back up funds and/or reserve funds, then all that we end up having remaining is our emergency funds, and at some point, we cannot buy bitcoin anymore with those funds.. since we hardly have any money left and we are down to the bare morsels and we will run out of whatever we have soon..
I tend to think that once we get to our emergency funds, our status/situation is devolving so badly that it is possible that we are going to end up having to start to sell from our bitcoin since our emergency funds are getting close to running out.. so it does not seem to make any sense by the time we get down to only having emergency funds to continue buying bitcoin with our soon to be depleted funds.. especially if we have a lot of uncertainty regarding the timing or the amount of our next incoming funds...
I also think that the duration at which you build your emergency funds particularly to sustain your expenses should also depend on the worst case scenario of income arrival fluctuations. I have had a situation whereby my salary was delayed for four months at my place of work(due to some leadership transition issues, but it was eventually paid), so I made it a point of duty to build my emergency funds up to 6 months of my expenses to create a tolerance for the scenario I experienced earlier and in a bid not to ever touch my portfolio in such cases and beyond that to give me more tolerance to get hooked up with another source of income if my previous source gets cut off without prior information.
I think for me 6 months is a very good timeframe to fix my finances in case of anything unpleasant happens as against just 3 months, reason I built my emergency funds to my comfort timing.
Many times, people attempt to imagine a variety of events that could happen, and sure some events are more likely than others, and so if you have actually experienced having your income cut off for 4 months, that becomes a very material event and perhaps even having decently good chances of happening again... so yeah, of course continugency plans need to be figured out when the negative event becomes more likely, and it might not even be considered an emergency if you know that it has high chances that it is going to happen, you just have to hold funds for that in your reserves.
I would not know the solution, especially since each of us has to try to figure out how to deal with our own cashflow management situations and to figure out how to assign likelihood and/or how we might prepare in the event such an occurrence might take place. Like you mentioned, we might try to find some kind of a back up income source or we may even decide that we do not want to have a relationship with an employer who had previously put us into such a problematic cashflow situation. I understand that there could be situations in which the pay from a certain employer is so good that it is generally acceptable to have some negative attributes that might include from time to time, delays in getting paid. In other words, we might decide to stay in a situation that has uncertainties in regards to timeliness in pay when the pay is generally better than other opportunities that we have available.