Yes, these Trijicon HD Night Sights are compatible with the M&P 40C.
The Trijicon HD Night Sights for S&W M&P only fit the M&P, M&P M2.0, SD9 VE, and SD40 VE models. (Excluding M&P SHIELD & C.O.R.E. Series). Trijicon does make a heavy duty night set that is compatible with the Shield Plus that you can find using the following link:
https://www.opticsplanet.com/trijicon-heavy-duty-night-sights-orange-front-outline-s-w-m-p-shield-sa139-c-600.html
Yes, the SD models will work for the SW9VE
Yes they will.
Front height: 0.215" Rear: 0.292"
Front: 0.215" Rear: 0.292"
The MP Shield version of these sights can be found in the links below:
https://www.opticsplanet.com/trijicon-heavy-duty-night-sights-yellow-front-outline-s-w-m-p-shield-sa139-c-600.html
https://www.opticsplanet.com/trijicon-heavy-duty-night-sights-orange-front-outline-s-w-m-p-shield-sa139-c-600.html
These sights will not work with the Shield EZ model.
Yes, you can use either just the front or rear of the Trijicon HD XR sights on your M&P 2.0 Compact, but please be aware that if you plan to use them with something that isn't a Trijicon rear sight you will need to verify your point of aim and point of impact with the new setup.
There is no official documentation stating it will work, however many users have reported success using M&P front sights as a replacement on the S&W Governor. We recommend installation by a qualified gunsmith as minor fitment may be required.