I like it in cases I just misunderstood something and they point out, why I'm wrong. Ofc with a disclaimer but even without they usually have good knowledge of the topic so they should also be heard.
I think this is really tricky. On the one hand I like other viewpoints to discuss such a difficult topic. On the other hand I don't want to get corporate shills. Also the filter bubble point, which brings you to only wanting to hear your own opinion. The way hackernews handles this most of the time is way better by letting people make a disclaimer.
We will also try to go this path. What is your overall satisfaction with this approach? I saw that grpc-web is marked as alpha and the grpc team itself wants to implement something which is kind of comparable.
I have a pretty similar project. But the problem with the mainstream moisture sensors is that they break after some time (or I did not find a good one). For myself I found the expensive solution a flower power from parrot http://global.parrot.com/au/products/flower-power/ a handy solution. It workes with bluetooth and they have some documentation. I did some working for python: https://github.com/Dlotan/flower-master-fab/blob/master/app/... and get good results over a long perioud without too many outliers
It helpes to stay in contact with not so close friends. For example people I met on a trip in canada. It makes me happy to see their vacation pictures which I wouldn't see usually because we are not that close.