Looking for a fast boot smart thermal sight. Any recommendations? From your experience, what is "safe" (beyond which it becomes annoying) boot time spec I should consider?

4-6 seconds would be fine.  I'd say it's one of the last variables I'm looking for in my decision .

Thanks. Smart sights usually take longer to boot...I should sacrifice the fast boot for "smart" features.

You thinking time to boot or time to stabilize?  Thermal scopes take some time for internal temperatures to stabilize after initial power-up.  Could be anywhere from 30 seconds to 5 minutes.  Also depends on environmental conditions.  Some, like the PTS from FLIR, have a standby mode where the core and electronics remain powered, but the display is turned off to reduce power consumption.  To me, that sounds like a better option than having to NUC every 30s-minute till it stabilizes.