Every second will be valueable if you can perfectly use it. It seems you are afraid if you coin get dumped after buying because bear is still on its way! but honestly nobody can accurately predict what will happen tomorrow. So you should rather divided your fund and invest with potential coin like btc, eth, xrp, bnb. If those get dumped then buy again and minimum the loss. Or you can wait. Potential coins will always pump.
Diversify your portfolio, I think this strategy is good for reducing investment risk,
all the coins that you mentioned are very worth buying and there is no need to hesitate,
take advantage of the opportunities that exist to make a profit.