I'm in Dallas, Texas, with a wide open view of the sky. Best signal quality I can get with the V8 Finder meter that came with the self-install kit is 74%. Does that sound right?
Don't have the BT meter but your signal on the tv is higher than I have here in central FL using a converted slimline. I got SS 83 SM 75. If a heavy cloud rolls over even with 100 signal will be lost. That's linear KU band for you. At least if locals are available can watch those until heavy cloud clears.
I was wondering what a good signal strength was. I use an old 76cm Winegard dish with PowerSat LNB I found next to a dumpster! It was getting 84/87. I bought a Maverick MK1-PLL LNB, and it went up to 87/91. There has to be very heavy rain in the SW sky to knock it out. I’m in TN, BTW.