There is no such thing as DCA and smart DCA. You seem to be referring to combining DCA with buying the dip, which may or may not be a good idea, but it is another way of DCAing, since you can accumulate BTC by three buying methods, DCA, buying the dip and/or lump sum buying.
As I shared that strategy is for experienced investors, not for newbies. With newbies, they lack of experience in the market and if they apply smart DCA or as you explained, a combination of DCA and buy dips, they will struggle to make their decisions for purchasing dips or wait for deeper dips and at the end, they probably will miss many dips and waste many great opportunities to buy discount bitcoin.
They can apply DCA for withdrawal or exit and don't have to predict a next ATH to take profit.
[ANN] JJG Sustainable Bitcoin Withdrawal Strategyhttps://bitcoindata.science/withdrawal-strategyI am not really too keep on any kind of an idea of using DCA for withdrawal, and sure, some might consider sustainable withdrawal as an exit DCA, but that seems a bit misleading to me, and in some sense there is not really any need to ever completely exit BTC, so the idea of sustainable withdrawal relates to abilities to perpetually withdraw (or live off your BTC or draw an income from your BTC) once you have reached a status of accumulating enough BTC, yet better yet if you have reached a state of overaccumulation, then you can likely pace your withdrawal so that you never run out of BTC...so yeah maybe in the beginning there would be more cushion or more conservative withdrawal and then if you see that the bitcoin is largely holding its value or increasing its value, then you could increase the withdrawal amounts. I do have some things that I need to fix and/or tweak in some of the withdrawal formulas in that thread and in the withdrawal tool too.
I don't think using DCAing method to withdraw Bitcoin is a good idea for any investor, mostly in when the investor is a Bitcoin newbie that haven't accumulated any much Bitcoin in the past. Why I do t think k it's a good idea to withdraw Bitcoin with DCA is because when the investor might be withdrawing and he's not making any profits and he is withdrawing it shows that the investor is losing. And the main purpose for anyone to invest on Bitcoin is because we want to make profits. I agreed with what you said that one shouldn't withdraw every Bitcoin he have because he/she took years to build his Bitcoin portfolio, so selling all what he has worked for isn't a good idea as once a good investor. We only have to withdraw little and hold on to the remaining and if we still have money in future to buy Bitcoin we shouldn't hesitate to do so..