I know this is an old thread, but I have some experience with the FTSs system that I think could be useful to others:
Ambient temps up to 77, is a little warm for a lager...but I found the neoprene sleeve that comes with the FTSs system to be pretty effective. Here’s my recommendation if you want to try it:
Fermentation
1) Pre-make some ice blocks using silicone loaf molds (I used the Traytastic available for about $12 on Amazon). Ice blocks melt slower than ice cubes and will reduce the maintenance for keeping your ice chest water cool. You’ll want 2 molds to be able to keep up with the ice block demand for several weeks.
2) cold crash your wort to pitching temp prior to putting in the fermenter...it’ll take too long to get it there with the FTSs system...it’s better at maintaining temp in my experience.
3) keep making ice blocks, add a few every day. I usually added 1-2 in the morning, 1 in the evening, depended on how the blocks were holding up. Having some made in advance will take the pressure off of you if you’re busy to have to keep making new ones.
Lagering
I just lager in my second refrigerator. Rack the beer to a second container, remove the shelf from the fridge, put it in and wait. It’s 40°F in there. Ive has good results with this method.