Buying at the dip is for those investors who have reached more than halve of their bitcoin target. There is no problem if such people wait for the dip to enable them add a significant amount of bitcoin to their portfolio, because they already have a good size of bitcoin in their custody.
I am not really opposed to your describing some kind of a goal for when someone might want to transition from pure DCA and start to supplement with buying on the dip, and I really doubt that you can be that particular in terms of when buying the dip systems might come in handy.
Let's say that a guy with $30K per year income had been investing into bitcoin fairly aggressively at about $100 per week for 3 years (that is 17% of his income), and so after 3 years, the amount that he invested is right around $16k into bitcoin which would be slightly higher than half of a year's of his current income, and maybe bitcoin went up in value during that time and maybe it did not.. but surely this guys is making a lot of good progress in his investment. I think that he has more flexibility regarding what to do based on his already existing progress.. sure there is no exact answer.. and maybe he get's a bonus of $4k, and should he invest it right away or should he divide it into the three categories.
Let's say that this guy's goal is to get his bitcoin to 10 years worth of his bitcoin in value, so with his current income, he wants to get his bitcoin investment to $300k in value in current dollars.. sure his income might go up and so he might have to raise those amounts as he gets closer in order to really account for 10 years of his income, yet for the time being, if you say that he has to reach half of his target, that is $150k, which surely seems way too restrictive from my perspective, and surely once a guy start's to get 1/2 to his objective, he could find he can get to his goal quite quickly.. or maybe he just gets stuck at 1/2 for a long time... yet I am also tending to use the 200-WMA in order to valuate my BTC holdings rather than using spot price, so even
right now a guy with a goal of $300k of value, he would need to have had accumulated at least 6.92 BTC, and so you would say that he would need to have had accumulated half of that amount 3.46 BTC before he could reasonably move away from a strict DCA approach.. which surely seems to strict to me, even though it is not unreasonable to consider those kinds of standards, even if someone like me might consider them to be too strict..
In the end, you have to figure out your standard of strictness, yet if you are suggesting that other forum members should have such a strict standard, that also seems a bit too much.