Not that I can think of. I've been a happy tmate user for several years, and the feature set is more than I need. The bad parts have just been reliability at some points over the past few years. In my case, I can only recall having bumped into this[0] one.
Termius has a free version that can be used on Mac/Windows/Linux/iOS/Android. We charge for sync and professional features. It's a common model for professional software, IMHO.
The pricing for Enterprise has changed. We are also working on additional value for bigger customers. Please let me know if your company wants to know more roman[at]termius.com
Btw, is there any feature that you always wanted in tmate? I'm asking because we are going to develop the Terminal Sharing.