Late summer when heat gets bad and things get dicey, I might implement fogging or misting to the plants at night and in the morning, as I plan on keeping them in a deep tub fogging might actually work. The temperature drops at night are significant here, so a fogging unit might help to condense onto the plant's mucilage and all that weird stuff I keep hearing about Drosophyllum.
My soil experiments will be limited to the number of plants I manage to germinate and keep alive. So far I think two compositions will be used in the final two large growing pots.
One with mainly COIR and sand.
One with mainly sand, perlite, and peat.
There may be some combination of a little perlite here or there as I eyeball things, the reason being that my silica sand is a rather small grade, a small portion of lava rock may also be used in either or both mediums.
Unfortunately, I don't have identical large pots, however other identical conditions may help abate this.