Buying on the dip is a great way for you to have a chance to make a profit in the future. And in this situation, timing is needed, or you should know how to feel or when to buy and sell.
Perhaps if you are using DCA strategy I see no reason why we should focus on buying dip, I no that accumulating during dip is also one of the best time but with DCA strategy we don't need to wait for a dip to come before we could start investing on Bitcoin.
As stated above by @Agbamoni, it is wise as an investor that us DCAing to also keep reserve of funds that he can use to buy at the dip, such incase bitcoin price dips, and he will still continue with his DCA strategy. This will enable you get to your bitcoin target faster than when you are only DCAing. This is because nobody can time the market but you can be prepared for the market by reserving such funds for the dip.
However accumulating on dip is for mostly those that lump sum because they want to buy everything at a stretch so they consistently observed and watched the market to see if there is any dip for them to lump sum.
No accumulating at the dip is not only for lump sum buyers but for everyone who has prepared and kept reserve funds for that purpose. A lump sum buyer can also buy anytime that he feels he should buy disregard of the price of bitcoin as long as he is investing in a long term investment because bitcoin price will be more likely be higher than the amount you bought 4yrs ago and above. But lump sum has more advantage if you are lucky to buy at the bottom line. Stay healthy in your bitcoin journey by using the three methods of accumulation bitcoin base on your income at the right time, to be a good long term hodler, you must be able to be flexible with your DCA strategy with the market movement of bitcoin and use the other two strategy when there is an opportunity to do so because you are prepared if the market goes south or west.