No it will not.
No, this is not compatible.
The Magpul CTR/MOE Stock Cheek Riser are only compatible with Magpul MOE and CTR stocks. This riser is for use on NON AR15/M4 applications as the riser will interfere with charging handle function.
Yes. The Magpul CTR/MOE Stock Cheek Riser is designed for the MOE and CTR stocks, it uses a clip-on installation, no hardware required. This riser is for use on NON AR15/M4 applications as the riser will interfere with charging handle function. Originally designed for M14 carbine stock conversions.
Yes, this would be compatible.
No, nor would I recommend using a heightened cheek weld on the ubr stock.
The Magpul ubr gen 2 has a fixed cheek weld, meaning installing a riser would make the charging handle unusable.
It will not be compatible with the MOE SL. The SL does not have the necessary side mounting slots for this to be mounted.
No, this riser is only for Magpul CTR or MOE stocks.
If it is a chassis model that includes the Magpul MOE stock, it will fit. It will not fit the standard stock models.