Thanks everyone for the suggestions.
I might be able to borrow an Android phone for a while.
All my kit supports BLE and I’m not inclined to purchase the dongle to allow the iPhone to connect to ANT+. However, I might be interested in something that will BLE to ANT+. I have a lot of older kit that only does BLE and it would be nice to be able to capture metrics on multiple devices. But that’s another topic!
And manual controls do work. It’s just not the same! I really do like the work out that mix it up. I tried straight up erg mode and I got so unmotivated in 30 minutes, I gave up!
If there’s anything I could do to help with testing, do please let me know. My $dayjob used to be software development and in a prior career was a QA for video games.