He doesn't *need* the dash grab though. The way I see his dash grab, coupled with Side B, is this:
1. The really long range dash grab is unsafe and overall is bad. There are very few situations where you will be able to likely get a grab, even during a tech chase, with the long range grab.
1b. At long range, if you expect to land a hit anyways, Side B is the better option. You can get the massively gnarly strong hit, or try to jump with it if you made a mistake. If they honestly shield at such a distance instead of reposition, then they are silly dumb and this doesn't validate dash grab. If you think you would grab them at max range with dash grab, just Side B anyways. Can give you a ton of reward and small risk.
2. At very instant close range, the move is laggier than regular dash grabs for other characters. At the very least, fix this part about Wario's grab because all it does is add more room for ****ing up. There's no depth or mixup for the "up close" dash grab, so why have it be so bad?
3. If we are keeping this dash grab, I would like to see it function more like his actual Side B. Give it armor to go through low % projectiles and jabs/etc, but have him lose the armor once he initiates the grab obv. If he has this already, I wouldn't be surprised because I don't use it ever and it's still silly.
Edit: Those changes to dash grab you suggested would be a bit silly. Auto grab would be very janky, based on how it detects hitboxes (think of how weird raptor boost can be). Being able to instantly cancel a dash grab, without grabbing, is a sick feint but again why the hell does Wario need any of this? He has enough tricky, gimmicky, mix up orientated crazy nonsense. Let's leave his dash grab alone. Make it a boring dash grab, because that's all a dash grab needs to be!