We've a couple of dozen, mostly ceramic pots with roses and other perennials in them. Over time, the root balls build up and what can happen, is that when I water them, a lot of the water can run down between the root ball and the inside of the pot. I made this tool that I use to force down through the root ball, a few inches from the sides in four places, three-quarters of the depth of the pot. I do this a couple of times through the summer. There's quite a bit of resistance to this by the root ball, so I need this handle on the end. This leaves four holes, so when I water the pots, some of the water will drain into the root ball via these holes. Those plants on pot movers, I make sure as well as watering the pots, I put water into the pot mover, so there's the chance of the bottom of the pot absorbing some of the water through the holes in the bottom of the pot by capillary action. This helps those on our patio, where as well as heat from direct sunlight, they get convected heat from the flagged area on which they sit. Each pot mover has a hole I drilled in the centre, which is presently blocked with a dab of silicone. I remove this in the winter months, so that the plants aren't sitting in water they don't need. In hot weather, I try to remember to give the foliage of these acer palmatums a mist spray half-way through the day, which helps prevent the leaves from burning.
DHR your watering strategy is looking good and consistency has paid off. You think of everything to keep all the garden plants happy during the heat that summers brings. Your acer palmatums are beautiful.