The name ProtonPlus fits the purpose of the app, but it unfortunately doesn't follow GNOME's naming guidelines:
A good name should avoid using trademarks or names of other projects (for example: GNOME Instant Video).
The current app name includes "Proton", and even though it does build upon the Proton compatibility layer, it's not directly affiliated with it.
A good name should avoid non-standard punctuation or whitespace (for example: SuperWriter).
"ProtonPlus" is not standard punctuation, and GNOME apps don't follow this convention.
Possible solutions
Awaiting an initial response from the GNOME Circle committee is of course possible, but they're currently a little behind on reviews, so it might take some time. I'm pretty confident that this is one of the things they'll mention first, which is why I'm opening this issue now.
If the app is aiming for inclusion in GNOME Circle, it should have a name that adheres to GNOME's guidelines and integrates well with other GNOME app names. I suggest "Cation". It follows the gudelines, it's what the new proposed app icon (#107) resembles, it's unique, and it fits the purpose of the app.
There are maaaaaany other possible names too, of course. The intention with this issue isn't to force a renaming instantly, but to start a discussion about it 😄