Looking forward to the Turris Enterprise!
An idea for an “add-on” to this would be a MAC-less GPON SFP stick, if that’s technically viable for the device.
At least here in Germany where I’m located, GPON fibre infrastructure is being massively built out, but there are no MAC-less GPON SFP sticks available (there’s one for AVM Fritz!Boxes named “Fritz!SFP GPON”, but that only works on that HW platform).
GPON SFP sticks commonly found on the market today, like the one I currently use in my Omnia, are actually full (very outdated, receiving no updates) OpenWrt Linux hosts that pass the traffic through and do OMCI signalling. In other words: That’s quite bad. (On the other hand, your ISP-provided ONT device may not get any updates either, and using a MAC-ful GPON ONT SFP is probably still the more energy- and space- efficient option).
I’m currently a user of the FS.com GPON ONT SFP stick, so it does work, although having another OpenWrt instance running on the stick is not ideal.