Bitcoin may have topped at 126k already and yes DCA is a good way to accumulate Bitcoin, the method anyone is going to use is on them to figure out, I still believe that using a large sum of money to buy good dip is better than buying at every five percent or ten percent drops, you don't have to wait on the bottom as it is very hard to know what the real bottom looks like but buying bitcoin with large amount at 40k is way better than using small portion to buy every dips.
All the ways you dropped are good and choosing one depends on the person, we don't earn money the same way, some get paid weekly and some monthly, there are even some who get paid several months later so we should choose one that suits our lifestyles and hold for the future, o believe that bitcoin will reach a million dollars one day. We are still very early.
You are very correct, every bitcoin investor cannot actually use thesame method to invest in bitcoin, and the method that any investor will choose will depend on how comfortable that investor might be. Sometimes, one might not even be earning regular income, and for such investor who doesn't earn regular income to engage in DCA it will be very difficult, rather buying bitcoin in lump some will be more preferable for such investor. On the other hand, someone who is on regular income can choose to invest either with DCA or buy in lump some. However, it will be more better for someone on regular income to engage in bitcoin investing with DCA method, because since your income is regular, small, and consistent allocation of fund on a long period of time can help you accumulate significant amount of bitcoin.