How should I schedule square jaw Botox injections so that the muscles shrink nicely?

Maybe it's because I love chewy food so much, but my jaw muscles keep developing, and it feels like my face is gradually becoming square. When I take photos, only my lower face stands out, so I've been getting Botox regularly.

I'm curious how often everyone gets their Botox injections. I usually visit again after about four months because my muscles start to feel stronger again. However, I've heard that getting them too often can lead to resistance, so I'm wondering if I should extend the interval to six months.

Is there an optimal timeframe to maintain the muscle-shrinking effect for the longest time after a Botox treatment? If anyone has switched to a product that doesn't cause resistance, please recommend one. I want to keep my slim V-line, but I'm cautious because I'm afraid I might ruin it if I get too greedy. I'm curious about the know-how of those who consistently manage their Botox results. Please share your tips in the comments!