OK, so my shoulders could be the bottle neck causing my current flat bench plateau? Seems likely given how shit I am at OH presses.
So I'll take your advice and implement OH presses as an accessory (i.e. 4 x 12) twice a week. FWIW, I will have to aim for less than a third of my bodyweight to have any chance at completing all four sets.
Then on the third day I do kettlebell carry.
But how to do a "static" exercise systematically? It's easy to find the correct weight for 4 x 12. But for a carrying exercise I will need to decide both X weight and Y number of minutes? Any advice appreciated.