I created a custom driver for the environmental and motion sensors. The entry sensors required nothing additional. I have the motions set, for the most part, to become inactive after about 2 minutes without another activation. This works well for my use case.
I replaced all of my aging switches in addition to replacing my zigbee and Z-wave sensors. The cumulative effect before and after replacement has been very noticeable. Everything, at least for me, has been very responsive, no complaints.
Reliability and responsiveness were the two things that I was chasing with my upgrades. I feel that I achieved that.
Good luck!
Edit - Thinking about the timing issue a bit more. The USL sensors did require different mounting location considerations. They are pet immune which also affects mounting location. As I think about my locations, I don’t think any ended up where the zigbee/z-wave sensors were. I did relocate a few even more after initial setup to achieve desired results. For example, they won’t see you straight on when mounted vertically and horizontally changes the range.