Your comments
This means that you can't configure Ubooquity at all because these is no local access to the browser and the remoteadmin doesn't work for initial setup (so it seems anyway).
That's not true.
Ubooquity does not require a local browser as long as you activate the "remoteadmin" flag in its command line.
Consider me reminded. ;)
There is a reason: lack of time.
Sometimes I miss posts. And I often fail to find the time to answer them.
Your idea is indeed interesting. But there are already a lot of feature in my backlog.
RAR support is not perfect in Ubooquity: it relies on a library (Junrar) that is quite old and has a few issues. But it's the only one available for Java.
Apparently, Junrar development has been active again in the past few month, so hopefully the situation will improve in the future.
Indeed, Ubooquity does not support SVG covers.
But it does not require epub v3 either. So I guess that the conversion had another side effect that fixed the files.
As for the launch script, if you have a better version I'd be happy to replace the current one with yours (as long as it remains simple, I want it to be an understandable entry point for users).
No promise, but I'll probably take a look.
Ubooquity uses H2 in embedded in-memory mode.
As far as I know, this mode does not allow multiple connections.
In any case, I think an API would be more adapted to your use case.
Customer support service by UserEcho
That's not true either.
As a lot of participants on this forum have proved.
I'm sorry if Ubooquity did not meet your expectations, but please refrain from such uncalled and wrong statements.