I'm no expert and I don't have all the answers but with luck and time I'll have fewer questions. All I can do now is share my observations which will possibly offer some clarity...or muddle things even more.
Keep in mind that SG is a measure of density. We like to think it's mostly sugar but with country wines that's not always the case. In addition to nonfermentable sugar alcohols I believe there are other compounds that simply settle with the lees. Some examples: my last tomato wine (a delicious tomato-caraway) had an SG prior to sugar of 1.024 which, out of curiosity, I decided to ignore. In less than 24 hours it went from 1.110 to 1.078, possible but I have my doubts. And flowers are generally believed to have zero sugar. I've made at least a dozen different flower wines and most have an SG prior to sugar of close to 1.000 but my day lily was 1.026, magnolia 1.016 and redbud was 1.024. And my rose hips came it at 1.050! Do I think that a quart or so of flowers has more sugar than 6 lbs of raspberries or blackberries? (Answer - no.)
I understand you want 1+1=2 but sometimes 1+1=2ish is what you get. I think most country wine ingredients obligingly follow the "wine rules" but some are determined to be different. Like the ground cherries. Do the research, make decisions, hope for the best, learn, repeat. At bottling time I don't effin' care about ABV or pH - if it tastes good I'm happy.
I hope this wasn't a non-answer answer. The ground cherry didn't have high ABV or harshness, both of which I've experienced. My high ABV dessert wines, balanced with no harshness, make me feel tipsy in a few minutes. They're some of my favorites!
And I like to think this is still a free country so you can be a Richard or a Karen
or both, doesn't bother me!