I think a dedicated thermal rifle with a normal thermal scope is the way to go. No taking stuff on and off wondering if it's still zeroed. Now they're coming with built in LRF and a reticles that automatically adjust based on the range and your ballistics. Rix DBH, Nocpix Ace 50, AGM adder V2 640, Iray rh502, or Pulsar XP60 all have LRF and ballistics, record video and audio, and have new larger displays in the eyepiece. The Nocpix also has ocular zoom that you can use to zoom in on the display itself.
No question. I know a lot of night hunters and not a single one employs a clip on.