I'd like to suggest adding a time based intensity target for workout reps. For example, you may have repeat reps that you want to complete in 'x' amount of time. This would make setting up workouts on a time based ratios much easier, e.g. 1:2, 1:3, 2:1 etc.
For example, 400m reps with a 1:2 ratio might have a target time of 1m 20s for the 400m rep followed by a rest of 2m 40s. Using a time based target makes it easy to see the ratio at a glance and modify as required.
Thanks.