Yes, with yabridge, it works very well for example with all the Valhalla Reverb plugins. But then there are others like FabFilter, they do not work so well. But luckily there are now native Linux FabFilter alternatives, like ToneBoosters EQ Pro, Tal EQ, ZL EQ, ...

It used to be the only way to do it (LMMS is still kind of stuck in that time period). Fortunately there are a lot more native plugins now.

Yes with yabridge but it is really brittle.

Yabridge works, and it's frankly incredible that it works at all, but it has some trouble figuring out where I'm clicking on EZDrummer. It's gotten better in the latest version of Linux Mint but it's still a bit off.