I wish they had added an option to equip a full armor set in one step. I change my armor so frequently based on the situation at hand and only occasionally have a need to mix and match. I always wanted this in BotW and it would have been a really nice quality of life improvement in TotK.
They could very easily have been a new selection wheel, as in, hold
down
on the directional pad top open the sages wheel and then select one.The armor loadouts would be excellent as well and for me, I would like a hugely increased horse activation radius. Having a horse feels useless in this game given that we have so many other vehicles to traverse the terrain(and sky/depths).
In general the game can take a huge amount of improvement.
A quick press of down is supposed to call the sages to you (as well as the horse) but in practice it feels pretty useless. Your idea of holding down to open a selection wheel would be great. The horse could be on there too for that matter.