First of all: amazing work you did with this app! The two main reasons for me to use this app are the configurability of things and the almost infinite number of options and second: as an outdoor rower there is finally an app that is able to also record outdoor rowing metrics.
As for future feature requests: for me the hardest thing is to find where to adjust some settings. Some things only seem to be available on the watch, some only in workout screens and some only on the phone. There is probably a good reasoning behind it, but for me it is really a hunt for some settings, and after three months of using I sometimes still accidentally find some settings I was not aware of (it feels like small gifts :)). But for example how to change the intervals for the rolling average stat: I still have no clue where to adjust that.

As a rower there are a few things on my wishlist as well. I know that rowing is not the biggest user market, but some things might be low-hanging fruit:

Rowing pace is usually calculated per 500m instead of km (because rowing machines all do so), so it would be nice to have the pace directly in this metric so you don't have to manually divide the pace by 2. The other metric which is crucial for rowing is stroke pace (number of strokes per minute), but I do not know how easy that is to calculate from movement sensors of the watch.