I think the drying times that you calculated with the pumice will be detrimental only if you water the plant/pumice while it is still wet. Beyond that, I think you may be over-thinking this and over-worrying. I get 1/8" pumice from General Pumice Products here in the U.S. I just sifted and washed a bucketful over the weekend. It is drying in big oil pans outside -- and right now, it's really cold here in SW Florida. I don't think it will be fully dry until Thursday, and that will be 5 days. Chris is right -- use unglazed terra cotta pots if you can. Even with pumice, they will remain lightweight. Haworthias in pumice shouldn't need to be watered more than once a week, unless you live in hot southern Florida in the summer. Even then, mine only get watered about every 5 days. You don't HAVE TO water a Haw the very minute its mix is dry. You can wait a day or so and it will be fine.

@Kawagoe(Home of SF 49ers Santa Clara CA) Just seeing this old thread. AnJan's pumice supplier changed they pumice that they use for Quick Dry. It used to be 10% fines. Now it is more like 60% fines and totally useless for gardening. I asked the manufacturer about this and they insisted they made no change. I actually believe they received a different product from their pumice mine supplier and they were totally unaware of it, and have no quality control for particle size. @dbarron How far are you from Idaho? One of the best pumice mines in the country is in Idaho and they have a WIDE selection of carefully screened pumice. Expect to pay about $25 per 50-pound bag of pumice, and about $30 to ship it. While it is not cheap, the fact that they screen and wash the pumice saves you extraordinary amounts of time. You can experiment with particles ranging from sand size (#7), to 1/8 inch (#8), to more traditional gritty mix material that is 3/16" to 1/4". I like to experiment with sand size particles in soil for plants that like a moister well-drained soil, like Aeonium. I use larger particles for normal succulents. I have even been experimenting with using huge 3/8" pure pumice with some caudex plants and Euphorbia.

Yes, the Gary Gragg videos. He has some beautiful trees, even though I find it a bit annoying to listen to him. I'm always thinking, "Get to the point already!" But, to your point, yes, the mounding and mulching is definitely going to happen here. Interestingly, the Japanese method mounds 60 centimeters above ground and uses a long rubber sheet that is that wide. They wrap it in a circle and tie it with some kind of nylon a bit more rugged than you would see on luggage at the airport. The soil then fills the circle and the tree is planted in there. five years in a 2-meter diameter circle, and then they expand to a wider area. We have an intense rainy season and heavy clay soil. I want to get those roots into the native soil, but I have heard some stories of the tap root getting rotted out after the trees have been in the ground for several years. I really don't want to have healthy trees for a few years only to have the rotted taproots be the reason they die. So, with that nightmare in the back of my brain, I keep coming back to digging a meter down and putting in some kind of drain to push water out and down the slope. I don't mind the rain going through the soil because I think avocados like that, but I want it to have a path to exit. Since avocados usually get a tap root of 1 meter, I figure I can dig down maybe 50 cm to install some kind of simple drainage system, cover with native soil with maybe 10 percent pumice and then build up 60 cm above ground with the same soil. I could add 25 percent pumice to the top 18 cm and heavily mulch.

Did you bring home fabric swatches (or order them online) so you can look at them in your home? It doesn't really matter what something looks like in a store because their lighting is not going to be the same as yours. If you're planning on keeping your rug you need to look at a swatch next to it. I suggest you consider that you already have a lot of light, warm neutrals in your space. If your sofa is the same color as your walls and close to the rug color the overall effect will be monotonous. Have you considered blue or another darker color? You might be tired of the brown leather, but it looks good in that room (and your cat matches it).