I've never been a big fan of large blades for tipup rigs so my opinion would be that 3s or 4s are definitely too large. They never really spin, just flippy-flop around and maybe make a little noise. I just can't get my head around that size blade. Especially when guys are fishing fluoro leaders for pike because they're "invisible" and then they hang a big gaudy blade on it. And yes, I know a guy that does that.
Smaller blades are a different deal. I've used a pair of tiny blades no larger than size 1 to provide a little flash and noise. Not magic but what really is?