There are very easy ways round the different sizes of service ports.
1234 still costing more than R134A is crazy, I would have thought that supply chain for 1234 would have be established well before rolling out this gas change, so that means that the cost of 1234 is linked to supply and demand, or just opportunism by dealerships etc.
R134A does seem to be dragging its heels in getting jacked up price wise, and only by jacking the price up will its demand be reduced - but there again, if 1234 had been made to be an actual drop in replacement for R134A then R134A prices could have been raised by EU regulations and so helped phase R134A out, but somewhere along the way some donkeys considered that there was no need to play it that way. This nonsense has been going on for years in other fridge gas sectors and crazy useless interim gases being launched to fill in when others were dropped and lots of time and energy was wasted until things moved on to a more stable next phase, before moving on again!