He is/was sending out little PCBs you can use to connect to your vacuum and flash Valetudo. The way this works is you're supposed to contact him via Telegram and send him a prepaid postal label for him to send the package to you.
I contacted him and told him I was interested but uncomfortable with handing over my address data to Telegram over a non-E2EE connection and asked him if he was using Signal or another E2EE messenger we could use instead. When he said no I asked him if we then at least could use Telegram's Private Chat feature, but he declined again (I forgot the exact reasoning, something about the chat not being synced between clients and he needs the label on another client that he wasn't currently on or something. I remember it being a legitimate reason). After that little dialog he suddenly sent me instructions on how to refund the postal label, told me I was wasting his time and immediately blocked me (just in his chats, not the community yet). Keep in mind this is from the guy claiming to free your vacuums from privacy invading China cloud vendors.
After that I went to one of the community channels, told them in the chat that Hypfer blocked me and if someone else was willing to send me a PCB. He then started to argue with me publically (I don't remember what was being said, but for someone whos time I was supposedly wasting he suddenly was very talkative) which I ended by saying I wasn't interested in arguing with him and I only came to ask for a PCB from the other people in the channel. He then blocked me from that channel. Then I went to another one to complain about this behavior which was immediately followed by a block in every available Telegram channel.

TL;DR: Guy creating non-privacy invasive firmware server alternative uses privacy invasive platform to manage community, blocks you when asking for E2EE alternative and gets mad when you tell his community how he acts.

All to say this is a really sad state of affairs. Valetudo could be a really great project with many many more users if it was just managed by someone with a slightly different mindset.

Think of Valetudo as a privately-owned public garden.
[...]
But, at the end of the day, you must understand that it is still privately-owned. You’re on someone else’s property over which you have no power at all. You will have to show the necessary respect. And - most importantly - you need to understand that letting you into this garden is a gift and should be treated as such.

https://valetudo.cloud/