All plugins are slowing down your app (and I believe they are still loaded on every page, even if not used on that page). Any time you can remove a plugin, you should.
In general, the best way to optimize your app and its performance is to follow the advice of the master, @petter. If you intend to do anything semi-serious in Bubble his book The Ultimate Guide To Bubble Performance | Buy The Book and really everything he writes, whether on his site or on the forum, are must reads. To start, you can check out these tips on the matter.