I think I know how to mitigate the splitpushing/lane swapping and a bit of toxicity in top lane

granted it replaces one negative element with the mandatory choice of another (which in of itself is negative) but it'd be mandatory like how flash is mandatory; it can be the source of really cool play making and be exciting to watch, use, and be used on.

Make teleport mandatory for top lane by causing teleport to only have a 60-90 second cooldown when used on friendly buildings. Teleport now takes 4-8 seconds to teleport to a building.

Now this mandates that a team should have at least 1 teleport to deal with split pushing. Since you can't teleport to a ward with a 60-90 second cooldown, the 5 man backdoor or splitpush can only be done very infrequently. At the same time, the defenders can still teleport to that building (or a nearby building) to fend them off just as easily while also having their teleport up in 60-90 seconds while the attackers have to wait a few more minutes. More importantly, it can cause some REALLY interesting plays when people try to tower dive since on one hand it can discourage people from tower diving but on the other, it opens up the teleporter to being interrupted and the cd being 3 minutes. The teamwork saving can be very interesting, like a teammate saving someone from a karthu or Caitlyn ult.

And no matter which side you're on, when you see that teleport animation on a ward, your first thought is "oh shit" and your heart pounding with excitement. That's a really cool thing to have in a game.

As to why shouldn't we just take teleport more often as is instead of trying to change it, the disparity in teleport cooldown depending on being offense or defense allows for some really cool tactical counterplay for both sides. Without that disparity, the meaningful interaction doesn't exist.

There are probably better ideas than this to help with the boring and sometimes frustrating splitpushing and lane swapping that goes on in LCS. However, I would like Riot to keep this idea on the backburner as a potential rough solution. Something being a mandatory choice is ok so long as that mandatory choice allows for some really cool interaction, like Flash. Yes, Flash is pretty much mandatory, and yes it's usually used as a get-out-of-jail-free card, but there are a LOT of instances when you flash initiate or flash escape or flash play that can REALLY turn the tide of a teamfight into the other team's favor and is exciting to watch and exciting to use. that in my opinion justifies the existence of Flash's near mandatory usage.

And for that reason, potentially making teleport mandatory on at least one player on each team will be an overall net gain for the game.