That looks a very nice one. Surrounded by the seat and bar = very nice secure feeling.
I would probably swap the abductor block for a strap up to the grab bar.
Two unistrut girder clamps, some 8mm studding, bolts and careful bending and I think I can do a grab bar to fit anything with rectangular tubing
Never thought of adding a grab bar...but there is one available for the convaid...
Although I did add a better push bar on the stroller, with a drink holder...used 1" emt and my bender was easy and does make it easier to push, the factory handles were a bit low for my ex, she was like 5'9"
But a grab bar might be nice...
Also, sounds like your giving parmrider a run for resident stroller guru!
P.s. I am assuming...you know electronics the EE...putting any electronics on your strollers?
Not at the moment, more important to enlarge things like seat back hight, seat depth and distance to footrest, plus bracing to deal wwith the extra load.