When I realised I could use double-sided tape to keep them in place instead of clamping, they were great!
The neck one was interestingly very tight on the sheoak for a PB neck heel, but almost loose with the paulownia on the St Vincent.
I also accidentally took a chunk out of the neck template acrylic, because I didn't let the router stop spinning before lifting it out. Fortunately, it's at the top of the template, so no harm done, other than cosmetic.