RE: SteemConnect 3, beta release looking for testers
Hi Fabien, yes, yes! Great to take this to beta level!
I've just tested signing the "Steem-uri" and it works flawless on https://SteemWallet.app which means people can also sign & broadcast SteemConnect based links with their mobile third party wallet.
For this I encourage you to change the "Open Desktop App" link to something more device agnostic, or detect when a user is on mobile :)
SteemWallet.app supports the steem-uri spec out of the box and your release is a great step forward!