Sounds like they have you covered. Try a few things out for yourself. It took me a while to get use to all of the HW nuance in an RV. Sometime I forget then I figure it out when im all wet and cold.
Once I installed the Oxygenic shower head my wife didnt complain about rinsing the shampoo. So put that in your Amazon cart now!
I prime the hot water tank first by using the kitchen sink and filling up a 2 qt pitcher about half way while watching the temp gauge. Once it hits like 110 ,,,,one of us will jump in the shower, bled the shower hose a little bit .... then your good to go.
I will use the pitcher water later (if boon docking) so its not wasted.
2017 Axis / 25.4: Big Foot Levelers, Aims 1200 Watt inverter, Ceramic Window Tint, Full River AGM 6V batteries, Front Hellwig Sway bar / Rear Track Arm, Safe T Plus Steering Stabilizer, PD 4655 converter, Hard Wired Surge Guard, WEboost + WiFi Ranger, LED Headlights/Driving lights, TPMS, Surge tank, Tornado flush, Viair Compressor