I think 30 hashtags is good. Currently my photos get like 700 impressions and about 80 of those will come from hashtags or about 1/8 of them so its a good little bit of traffic. Instagram also recommends that you use 30 in every post in order to grow your profile. Don't worry about shadowbans, it only seems to happen when you post a ton of pictures in a row with the same hashtags, for me the last shadow ban only lasted a day so only a couple of my posts didn't get impressions from hashtags and you can see this if you have a business account.