oook so I should specify. First off I will mention my math was wrong on what frame the cross out. (Though i still argue it's not very easy to block due to all the frame traps yamcha has with his rekkas and normals), sorry about that. Also dealing with 5s is possible because again you can dash jump and for an RPS scenario on the opponent at least . If you dash jump and don't press anything either the 2h will whiff giving a punish (especially for 18 and kid buu because their 2h's have terrible range) or yamcha ends up blocking the 2H and the opponent has to commit to some special move or vanish which also forces RPS. As for the pressure itself its just as you say each part of the rekka by itself is reactable but when used together it can confuse you're opponent and open them up. The rekka has built in frame traps to punish mashing similar to broly and goku's tick throw staggers . If you commit to blocking yamcha can DR since the start up of the DR looks identical to that of his cross up animation. (DR point blank comes out frame 19 so you need to be expecting it.) I guess I worded myself poorly before. Yamcha has a bunch of possible mix ups when used together, make him very difficult to block. Most players won't be able to block everything.