Yeah, of course Reaper also supports all types of plugins, including of course all types of VSTs (32 or 64 bits), and DX, LV2, etc.
But sometimes the thing that you need does not exist. I needed a "MIDI notes compressor" and couldn't find one, so I wrote it (the compressor brings all notes to a chosen range, so for example if the range is A3-A5, a C7 will be converted to C4).
It's a lot more setup but I've had a good experience with redux, redux-persist and localForage. localForage picks the best available browser storage API. One can select which subset of data to persist with redux-persist. It does assume a redux buy in...
Unfortunately, the CALF series have been notorious for having problems or causing crashes in the past. If you do want to try it out, I highly recommend getting the latest version or building from git as a lot of distributions package an older version in their repositories.
Things are slowly getting better if you want to run Windows VSTs under Linux. I found this very interesting as a overview of some of the current possibilities: https://www.youtube.com/watch?v=jsZnSg4DKDU
It is a demonstration for a proprietary DAW, Bitwig, but he does talk a lot about Windows plugins under Linux that I imagine applies to Ardour as well.
If you follow the "Ready-to-Run Program" prompts on the official download page[1] as an anonymous or unsubscribed user, you will reach a page that explains their method/philosophy.
I'm sure Paul would be happy to speak to you on IRC (#ardour on Freenode) about successes/failures but of course I can't say this for sure.
Also, I am awaiting a stream of Paul's upcoming talk (as I can't get to France for LAC2017[2]) "20 years of Open Source Audio: Success, Failure and The In-Between"[3]. I hope part of the talk will address the financial aspects that are of interest to you.
I've recently adopted a similar approach. I have a virtual machine running the same OS and version as the target production machine. I'm using QEMU and connecting to it via ssh.
I wrote some plugins for fun a few years ago in Lua: https://github.com/robsco-git/ardour-plugins
My understanding is that the plugins one writes for Reaper are compiled on the fly so I imagine they offer better performance.