I probably have a little bit less experience than you, but I'll still give you my piece of mind on this question. There are 2 points I'd make:
1) It's pretty much assumed that one never really stops botting on IG (or Twitter for instance) accounts. There's no real use in stopping, since it keeps on growing your account. If you have found good settings that keep you under the radar, grow your account and gives you good engagements, why would you stop? I'm guessing it might be to cut costs on VPS renting etc, but realistically if you have >50K followers you could start monetizing the account a bit and pay for your VPS from that.
2) If you're really looking to stop botting, I guess the biggest indicator that you can or can't stop is the unfollow period. I personally don't "like" any pictures or "comment" any pictures either. I solely do follows for X days until I reach ~7K follows (the IG limit), then unfollow for X days until I reach 0 follows. Then follow again, etc. During a "follow" period, it's normal to have the account grow a lot and get tons of new likes even on old pictures. During the "unfollow" period tho, that's when you need to see if your account is still growing, because that's purely organic.
I personally have one account which is closing in on 20K followers now. Just last week it started to really grow organically. During the follow period I used to get about 300 follow backs (from around 600 follows/day). Now I'm getting around 1K per day, and thus around 350-400 per day even during the unfollow period. Not sure if it'll continue like this, but I think it's a good indicator that the account has organic growth.
It's up to you to decide which growth suits you. What I do is set targets (for instance 50K followers for that account), calculate the average daily growth for the past 10 days and see how many days it would take me to reach that goal. If your goal is 100K, calculate the organic growth of your account (during an unfollow period, as stated above) and see if the pace would suit you.
Again, I wouldn't stop botting myself, but if you're looking to stop that's what I would do.
Hope that helps.