I'm following the Garmin Coach 5k workout plan recently and encountered the font size issue. I just can't read my HR information from the AMOLED screen due to its tiny font size in use, the situation is even worse in night running.
There is no such problem in regular running activity as its data screens coud be customized. If I want a bigger font size I could display a smaller number of data field. If I want to display more data field at the same time, I have to accept a smaller font size.
Just find an similar issue is reported in the "Venu 2" group. Hopefully the same issue in "Venu" could be resolved together with "Venu 2" at the same time.