My plugins require adoption of API changes introduced in R16, in addition to recompilation. I'm sorry to write that I have not made efforts yet to deal with R20 compatibility.
It is simply that I have much less time now than I had when I made these plugins. And, there are also other things which I want to give higher priority. Moreover, my plugins will remain closed source.
It is not out of question that development will continue for at least some of the plugins. But do not expect it any time soon.