Only trouble with non straight throws being allowed, as a lineout jumper back when I played, if a ball was crooked I almost never jumped, as it a mental thing.(well was with me only jumped if I thought I could win ball)
The other side of course you would always have to jump. and so would make it easier to score maul tries from lineout.
Nice points. But I do challenge your idea. The rules won't be perfect but if they make the game better 'most of the time' then they should be changed.
I would say teams are currently trying to get guys in the air 9 times out of 10, on the occasion they don't, like trying to defend a maul on the try line, the attacking team are going to win the ball 9/10 anyway, the only way they don't is from a bad throw/miss-timing. So it will probably only make 1-10% tries easier from a line-out anyway and for me, that is a little price to pay to speed up the game.
Obviously all made-up statistics, but hopefully they still make the point i was trying to make.
On the mental aspect, I think given how professional teams are these days, it should not affect these guys.
I would at least say, they could change the rule so quick taps are taken instead of scrums for things like crooked line-outs.