Submithub added a few features to their Influencer Campaigns since October 2022. I've found the budget feature allows for multiple posts to take place at a reasonable price, and when submitting with instructions there is a referral message sent for approval of the post.
In comparison to the Submithub playlist campaigns, one positive is the influencer campaign won't charge credits unless the influencer posts with your song; Instead of losing credits upon being denied from a playlist curator. I usually select the TikTok and Reel options while unchecking the Story option, due to the greater longevity of posts on the official sound. Also, influencers are required to @tag you in Stories and there’s now a minimum share length of 10 seconds.