The high-capacity pantograph charger/gantry is inspired. Since it's so far overhead it would appear to have some durability and safety advantages. I'm guessing that 6 minutes for 50kW is enough for charging in the field at the start/end of a route. Heck, now I'm wondering if you could get a substantial charge in the time it takes to onboard passengers at a stop.
Edit: exercising my position as an armchair engineer, this idea could still work but I think a business focus as making kits for adapting existing EVs to the gantry system, along with manufacturing the gantries themselves, would be way more viable than building entire busses from scratch.