I've also find this video

https://www.youtube.com/watch?v=GGHDd11PDNo&ab_channel=ProgressBar

Guy talk about website, which looks and sells exact same products as RissMiner. In the comments section, there's a plenty of guys who are saying this company is scam.

Domain was registered only on 26th of ...

I'm also looking in to RissMiner, by exploring forums and reddit, they seem legit. I dropped them an email message as well.

In Reddit, they said, that they also provide phone number per request. Have't seen any negative review so far. Maybe there will be more opinions?