It isn't complicated. Set the ride height for shock mounts at 50/50 with whatever pile of stuff you typically carry along when you want the optimal shock performance. If you want that optimal performance while rock crawling with a hardtop, full hard doors, a big cooler full of ice cream, wife, girlfriend, all three mastiffs, and every tool you own, then that is what you build the shocks around.
The greater the variance from that configuration's weight, the more the ride height will change and the more the shock's performance will be affected.
For perspective, understand that filling up an empty gas tank sinks the rear about 1/4" with about 90lbs of fuel. You can calculate that more specifically with your spring rates. Or you can simply measure and watch while you stand at the pump. Tools, gear, and body weights are all going to meander a bit over time. The dogs die.
The biggest problem comes from guys who build shock mounts with a completely naked, empty, unloaded Jeep. Then later on pile in a few hundred pounds of gear, full gas cans, and a RTT and wonder why the shocks are bottoming out.
