How about splitting LibreELEC into different editions
Eh, no. I don't think anyone wants to be the messenger telling the LE developers that they'll need to work 5 times more as from today.
LibreELEC MediaCenter - That's what it is today already
LibreELEC Server - Kodi is a CLIENT application, not a server variant
LibreELEC Minimal - What do you think JEOS means?
LibreELEC Legacy - There is a limit to what you can/want to support in terms of old hardware.
LibreELEC Ultimate - Oh, we don't need to change anything? Great! 
Display MoreEh, no. I don't think anyone wants to be the messenger telling the LE developers that they'll need to work 5 times more as from today.
LibreELEC MediaCenter - That's what it is today already
LibreELEC Server - Kodi is a CLIENT application, not a server variant
LibreELEC Minimal - What do you think JEOS means?
LibreELEC Legacy - There is a limit to what you can/want to support in terms of old hardware.
LibreELEC Ultimate - Oh, we don't need to change anything? Great!
Okay I fully understand that but this is not what I was asking for.
If we look at LibreELEC as a Linux Distribution like let's say Ubuntu then why would it not be possible to select in the installer what packages or what flavour (which could be my suggested variants) should be installed? In that case, apart from some tweaks to the installer, nothing has to be changed as we have the full repo already? And yes, Kodi is a client but it comes with a SSH, SMB, SFTP, UPNP, DLNA and so on server which might not be needed by everyone so why not give users a choice?
My intention is not to make the LE developers work five times more, it is rather to make LE even better than it already is.
You can try setup home router with USB storage with services you mention, only DVB drivers for tv reception need to be included to firmware but openwrt firmware alow for that and have howto how this could be done. Packages for multimedia in openwrt :
Minidlna , tvheadend, minisatip, oscam, xupnpd, bittorrent downloaders/..., Home automation, sdr, etc...
To build LE without Kodi is not that difficult, basically "just" a change that a console is started instead of kodi, an setup utility need to get written to setup LE (this could be done manually too but nobody really want that) and a bash/python "addon" download tool.
A barebone server version was already done, with some manual effort it is easily doable even today.
There was an RPi3 version (very stripped down) without kodi for some special software that was around 20-30mb in total.
