Quick update - v5 enclosure printed and contains everything relatively neatly, the only problem is the battery cable is too short for the battery that fits inside so while it's inside the enclosure, I've attached a separate battery for the time being:

You can see more of the internals below:

As you can see, the sensor is now mounted to the lid (reused from v4 as it didn't change) and the battery takes up a bunch of the space in the lower section. The screw holes in the bottom are in overhanging sections so the battery just slots in underneath.

I need some kapton tape to tidy things up on the fixed-up battery, but overall things are pretty much self-contained now. As mentioned in previous log, I'll be investigating putting the Qt Py to sleep and waking it up using capacitive touch, though I might take a break this weekend. :)