Sandra, thank you so much for all of that information! It truly does help to know that even though my frosting needs help, my train of thought is on the right track!
Even though I've been baking sugar-free for years, I never really tried my hand at frosting. We used to use the whole Cool Whip Lite/sugar free instant pudding hack to make frosting, but my stomach never thought it was such a great idea! LOL So when quarantine began and going to the store wasn't the best idea--since I'm in NJ--it forced my hand to try something new with what was in the house. Thus my current cream-cheesy nemesis was born.
An aside note: the "tropical cream cheese" coconut frosting actually was really good! I used it to cover and decorate my scratch SF devil's food cake, torted into four layers. The top and bottom fill was some of the frosting mixed with flaked coconut; the center fill was a scratch SF chocolate custard. Voilá--a Mounds-bar-inspired birthday cake. Definitely a combo worth repeating!
If you liked the Cool Whip option, you should try stablized whipped cream using gelatin. You could certainly use a sugar substitute to sweeten. Actually, toy don't even need the gelatin as long as you whip the cream until it is very stiff, just before it turns into butter. It makes a wonderful, light substitute for frosting.