DCA strategy in investing and DCA strategy in short-term trading are different.
It's better to make a good profit and then cut your losses from that profit. It's easy in your way of thinking.
For example:
1) Too risky: 1/4 of the profit
2) More safety: 0.25-0.5/4 of the profit
The standard stop-loss in the DCA trade, in our experience, should be at the resistance below the high timeframe resistance levels. Most of the time a tight stop-loss will be hit and the price will pull back.
You are talking about trading and not investing.
Someone who is investing might be adding to his bitcoin stash for 4-10 years or longer before he even starts to think about selling any, and even if he starts to employ some selling strategy or stops DCA buying on a regular basis, he may well not sell very much of his BTC at any one time, unless there might be some specific reason for selling. There may also be some rationale that once the BTC stash is established or sufficient in size, then why sell large portions of it, and so in that regard, there may well be an idea of long term holding and just shaving some off from time to time, whether the shaving off is price-based or time-based.
We surely might not know what the market conditions of BTC will be in 4-10 years or longer by the time we might want to start to sell some of it, yet some people might have some specific things that they want to buy, such as residential property, and even if residential property might not be a superior place to put value, there tends to be some motivation that people have in regards to having ownership over their own place, which also might not necessarily result in needing to sell most or all of their BTC at any one time.