Hopefully, you realize that if you are DCA investing, then you are going to have some invested DCA amounts that reach 4 years sooner than others, and if you lump sum invest into bitcoin, then surely those lump sums should have at least 4 years to mature, and hopefully no one is thinking about just getting in and out of BTC with 4 year minimum timeline, absent some compelling reason, and most likely they are going to be better off to start some kind of price based and/or time based withdrawal system with their BTC rather than just getting in and out.. absent some reasonable basis.. So if there might be ideas to draw income from an investment, yet other times, there are reasons to complete draw the principle rather than merely drawing income from the investment.
Yeah I got your point concerning the in and out, is like after one has reached the point of having enough bitcoin stashes in their portfolio, is not encouraging , for that individual to go all out when withdrawing from their investment ( withdrawing everything). But rather find a system or method he or she can use when it comes taken profits from their investment without, selling all their bitcoin. And it's actually a nice thing to do because after holding yah Bitcoin for like 4-10 years , bitcoin price may not be the same again, it may even be far more higher than we never imagined it to be . So selling all your investment won't be smart because you literally accumulated Bitcoin when the price was low during those years , and you may not have the opportunity to purchase Bitcoin at such low price again, like how folks that purchase Bitcoin during the price range of $100 don't have the opportunity to purchase it that same price agaij because the chances of Bitcoin going back to that range is too low ...
Just as @JayJuanGee said, smart enough should be decided on the purpose or urgent need as why the investment is being withdrawn from. Without any compelling reasons to fasten the selling of the investment, certain restrictions should be considered not just on timely basis which does not look truly proficient to give a good return of investment at when due because of volatile nature of Bitcoin at when due but for a more return in capital invested, specific prices should be targeted, it should flow sequentially which should actualize further profit on each sell order completed. Investors who are not too old of age can bliss on partial withdrawal and decide to reinvest percentage of their portfolio back into Bitcoin, practically for those who started by DCA approach this should help strengthen their portfolio.