Buying the dip is the obvious choice for anybody who is willing to hodl long enough.
The hands should remain still and without any shakes.
I disagree with you here. Buying on dips should not be the original strategy that an investor is using to accumulate Bitcoin for long term because buying on dips requires you to time the market and timing the market is an obvious act of trading. You can accumulate Bitcoin with either DCA, Lump sum which ever strategy you can be able to meet up with. Any strategy that will limit you to buy Bitcoin at any giving period while waiting for the perfect time to buy is trading and before you know it you made end up not buying any Bitcoin at all.
Also, Buying on dips does not limit to continue with your original strategy. You can DCA and still buy on dips if you have more discretionary income, you can as well Lump sum and still buy on dips too. Buying on dip can happen anytime and it is a good way to accumulate but the disadvantage is that you may wait for long before the dip will come and if your investment is a two year accumulation investment the years may elapse but only small amount of Bitcoin you will be having in your portfolio.
When you are using the DCA strategy to accumulate then you will surely buy during the dip along the line, for example you are using DCA strategy to Accumulate weekly and a dip happens within the week you want to buy Bitcoin and you bought as usual you have brought during the dip meaning you have benefited from the dip so there's no need struggling to make sure you buy or accumulate during the dip and there's no need waiting for a dip accumulating Bitcoin using the DCA strategy gives you different opportunities and one is accumulating Bitcoin during different Bitcoin price level.