Mike,
All I know is, early in my career I didn't build all tees with a sand cap, but when I didn't, the core aerified, top dressed heavy for a few years to correct that mistake. Golfers couldn't achieve the basic function of putting the tee peg in the ground, so the tees were deemed failures. I still resist, often using old green mix or a dirty sand not to USGA standards to save money on the tees, but even a few of these get complaints as being "too hard".
As to tee size, I have started making them somewhat smaller, expecting less play than the hey day, and also after interviewing my supers. Way back, I figured you couldn't make them too big on a busy public course, but when a few supers told me it took more than the standard 8 hour work day to mow them, I figured I better cut back. The mix does allow slightly smaller tees, so it sort of balances out cost anyway.
By smaller, I mean 6K and maybe 8K on water holes and par 3's, as opposed to 7500-8000 and 9-10,000. The back tees, which no one used can be as small as 15 x 15 feet, quite a savings. I also pay attention to tee marker width, doing tees at multiples of the typical 15 ft. setting width, to avoid too much wasted space, and minimize tee size.