I have the FF7 since December 2021 and the "Sanitize" cycle is a joke. It uses hot water that comes in at whatever temp the water heater is set, minus cooling down thru the water pipes on the way to the washer, then tumbles the wash for 60 minutes (the owners manual is free on the SQ website) while the water cools down a bit more during the tumble action. The manual states to use Oxygen bleach and apparently SQ believes that alone will sanitize with whatever hot water temp any given consumer has arriving at the washer. Whatever.
While 'sanitize' can simply be defined as 'to make clean', this is a marketing ploy and it shall not be confused by this consumer with 'disinfect.'
So far, I haven't used the Sanitize cycle because having items tumble around for an hour does not appeal to me. Our household doesn't need to disinfect anything, and our elderly dog has since died, so this isn't a big issue.
I miss having an internal heater (our Miele did), but other factors led me choose to the SQ FL over other brands that have one. It is what it is. I lived with an non-hE TL for decades that had no heater and we all survived. ;-)
If SQ came out with a FL with an internal heater, I'd trade this thing in before you could blink an eye. It was nice having one, but we'll be fine without it.
Without the internal heater the pillowcases come out smelling clean by adding STPP, so it was simply an adaptation. (we use unscented detergent, so if it isn't clean, I know by smell; there are no perfumes to hide unclean items.)
I'm still pleased with the washer and have no regrets.