The Vector Optics Frenzy-S is compatible with the Glock 43X MOS (optic ready) model pistol.
Yes, the Vector Optics Frenzy-S uses the RMSc footprint and will be directly compatible with any optic ready P365 model pistol including the P365, P365XL, P365X, P365 X-Macro etc.
Yes, since the Vector Optics Frenzy-S uses the RMSc footprint, it will mount directly to the optic ready slide of a P365XL without the need for an adapter plate.
Pressing both the brightness up and brightness down buttons at the same time will shut off the optic. Pressing a single button will turn it back on. The Vector Optics Frenzy-S also features shake awake, meaning it will turn on when it detects motion, and automatically shuts off after 2 minutes of inactivity.
The Vector Optics Frenzy-S 1x16x22 AUT Red Dot Sight is not compatible with a Keltec P17.
The Vector Optics Frenzy-S 1x16x22 AUT Red Dot Sight uses the Shield RMSc optic footprint. You would need to use a Leupold Deltapoint Pro adapter plate, found by using the link below:
https://www.opticsplanet.com/evolution-gun-works-leupold-deltapoint-pro-sight-mount-for-glocks.html
The Vector Optics Frenzy-S 1x16x22 AUT Red Dot Sight will not fit a Sig M17.