Yes, it will "Shake Awake" feature.
Yes, the Holosun HE503CU Green Dot Sight will mount to the flattop rail on your M&P 15-22.
The Holosun HE503CU Elite Paralow 1x20 mm 2 MOA Green Dot Sight can be uses with an Aimpoint T1 pattern low height mount to bring to optic as low as possible. However, even with a low mount, you won't be able to co-witness using standard AK iron sights.
Yes, the Holosun HE503CU Elite Paralow 2MOA Green Dot Sight has been bench tested to 1000G recoil during design and a statistical sampling is tested during production. Holosun optics are able to take the recoil for larger caliber firearms including .308 and 12GA shotguns.
Yes, the Holosun HE503CU Elite Paralow 2MOA Green Dot Sight will work with a 3X magnifier.
Yes, this optic can be detached from the mount and The Holosun 503 is compatible with the Aimpoint T1/T2 mount,
The included high mount provides a lower 1/3 co-witness with standard A2 height sights. The Holosun 503 is compatible with the Aimpoint T1/T2 mount - there are tons of co-witness mounts out there for the Aimpoint T1/T2.
The Holosun 503 is compatible with the Aimpoint T1/T2 mount - there are tons of QD co-witness mounts out there for the Aimpoint T1/T2.
The Holosun 503 is not available in desert tan/FDE, but the Holosun 403 is.
https://www.opticsplanet.com/holosun-paralow-hs403a-red-dot.html
Yes, Holosun does make flip back covers that should fit this optic. We do not have them available at this time.