You need to look ahead.

Steel Challenge will probably create a carry optics division for rimfire. If and when they do, competitors will want a bigger window than the current crop of RMSc footprint optics. (Carry optics division requires that the optic be mounted on the slide.)

IDPA may also create a rimfire carry optics division.

Smith and Wesson for sure and probably Glock too will come out with slide mounted 22 offerings.

Pistol shooters often have trouble finding the dot. A dot optic with a larger window will help. Firearm trainers understand this and will want options.

If you think 22s are just for plinking, you're mistaken. That bus left a while ago. Note Federal's new 22 LR Punch ammo for self defense.

Sig is an innovative and opportunistic company. Don't expect them to stand still with respect to 22 LR.

At this point, what is your point. We are way off the OP and any relevance to the Armorer section so this discussion needs to go elsewhere. I'm glad you can predict the future of the SC class structure and the product lines of major mfg. If you want a bigger optic at the moment get a gun that allows that (like a victory or ruger mark). There is no class for slide mounted rimfires that I am aware of. Let's just call it a day. Sig is not going to tell you the max weight for a 322. Nor is any other mfg. At some point maybe somebody will design a .22 pistol that works with the optic you want. Be happy go shoot.

This thread has taken an odd turn. Everyone is entitled to their opinions. Yours are off base in my opinion but that’s why they are called opinions. If you are comfortable with 22 Punch as your carry round then more power to you. 22’s will always be primarily a plinking round or small game round to me. I’ve carried it as a SD round before but it is the definition of better than a sharp stick in the eye. What this has to do with max optic weight I have no idea.