I am a network engineer and I had been using Termius in the MAC for about an year now.But whenever if there is a need for log collection, I have to use MAC Terminal. Because I cannot scroll with the mouse and select the text. This is a big disadvantage for me. (I don't want to press cmd+A and do a select-all)
Also it will be better if the list of connections (and folders) are displayed readily accessible always in the left or on the top.
I have not used the app in mobile. Because I am skeptical to store the hostnames and IPs (and definitely passwords) on a third party application.