The spools of bend insensitive fibre are pretty cheap and very discreet so I'll probably have a couple of those running along skirting boards/etc in order to connect disparate areas of the house. (The ONT is ~15m away from where the majority of the equipment will live, that's the main bit I have to bridge.)
This vid comes to mind when you said bend insensitive fiber: https://www.youtube.com/watch?v=Z2FbzCyiNr4
But, yes, that video is exactly the kind of thing I had in mind for the bend insensitive fibre.
It all depends how I set things up (and I can't tell that until I've had more access to the property). The ONT and the rack with the USW-Aggregation switch are 10 yards apart, in terms of absolute distance, but probably 20 yards if you follow the walls/skirting-boards/etc.
The FTTP is presented as 2.5GbE Ethernet (apparently) so I can either:
a) put my Unifi Express 7 next to the ONT and then need a fibre run (something like https://uk.store.ui.com/uk/en/category/accessories-modules-f...) from the SFP+ port on the Express 7 to the USW-Aggregation in the rack.
However this will be sub-optimal in terms of Wifi and I'll probably need extra APs to cover all three floors and out into the back yard.
b) put my Unifi Express 7 in the hallway in the middle of the house (which should give me full Wifi coverage with no extra APs). This would mean a short (2m) DAC to connect it to the USW-Aggregation nearby, and I can use a 20m long flat/flexible Cat-6 Ethernet cable to go between the ONT and the Unifi Express 7.
For the benefit of other folks reading, I'll note that even regular, boring OM4 bends okay. I have mine running along the outside of preexisting molding and baseboards. My runs get down to a 1/4" bend radius in places and it seems to work just fine. Bend-insensitive fiber is definitely useful, but it may not be required for the run one is planning.
Though, one thing that regular OM4 is not is discreet. That two-strand cabling in its aqua-colored jacket is quite distinctive.