My 7-year-old female cat has been progressively licking/grooming herself bald, and I'm hoping someone here has dealt with something similar. I'll attach pictures showing what it looks like now.

I adopted her about a year ago. When I first got her, the underside of her belly was already noticeably bald, but over the past year the bald area has gotten larger and has started spreading onto her legs. From what I can tell, she is licking the hair off herself rather than the hair simply falling out.

I have already taken her to the vet for this. They initially gave me antibiotic/medicated wipes and allergy medication, but neither made any noticeable difference. I'm trying to figure out what would actually be worth pursuing next before spending money on another visit/testing that may lead nowhere.

One thing that makes me wonder about a behavioral/stress component is her history before I adopted her. For the first \~6 years of her life, she apparently had a pretty rough home. She was sometimes left alone for extremely long periods, reportedly weeks at a time, and I was told she was dragged by her tail and potentially hit. She also used to poop in her previous owner's bed and hide it underneath the covers. Eventually the previous owner had to leave the country to seek mental-health treatment, and the cat was rehomed to me.

Since living with me, she has changed a lot. She has become extremely affectionate and trusting toward me, follows me around, sleeps with me, and generally seems much more comfortable. We are very attached to each other.

I asked my vet whether boredom/anxiety could be causing the overgrooming. I'm a college senior preparing for medical school, so realistically I only have dedicated play sessions with her around 1–2 times per week, although I interact with/pet her throughout the day. My schedule unfortunately means I can't dramatically increase active playtime.

The vet told me that cats that compulsively groom themselves bald usually develop the behavior earlier in life, so they didn't think boredom or anxiety was likely. What confuses me is that she already had a bald belly when I adopted her, so it seems possible the behavior actually DID start earlier and has simply gotten progressively worse.

Otherwise, she seems normal and happy. She eats, drinks, uses the litter box normally, seeks affection, and doesn't seem obviously distressed.

For anyone who has dealt with this:

Does the location/pattern in the pictures look consistent with overgrooming?  
Can stress/anxiety-related overgrooming gradually spread from the belly to the legs like this?  
Could her previous living situation have created a grooming habit that persisted even after she moved somewhere safer?  
Are there medical causes I should specifically ask a vet to rule out before assuming it's behavioral — fleas/mites, food allergies, environmental allergies, pain, fungal issues, etc.?  
If it is boredom/anxiety, are there things that have worked for your cat that don't require hours of active play every day? Automatic toys, food puzzles, window enrichment, routines, etc.?  
If I do go back to the vet, what tests or questions would actually be most useful so I'm not just repeating the same treatment?

Cat balding, is she bored?