Bookend workouts work around
Until we have official support for Bookend Workouts you can use this work around to create them.
For this example, let's say that we want to make this workout:
Run 400 m
then 3 rounds of
5 Air Squats
10 Pull-ups
15 Push-ups
then Run 400 m
To make this workout we need to set the number of rounds to 5, because
1 Run + 3 Rounds + 1 Run = 5 Rounds
For the first round we will set the first exercise to Air Squat and then add two more exercises, one for Pull-ups and one for Push-ups. We are leaving out the runs for now so that the middle three rounds will be generated for us and we'll only need to adjust the first and last rounds.
For the first round we want to change the first exercise to Run and then set the distance. Then for the other two exercises in the first round we want to change the exercise to Not Applicable and clear out any of the settings for that exercise. We can then do the same thing for the last round.
Here's what the first two rounds would look like:

You'll need to adjust the suggested name and description as it'll have Not Applicable in it.
While we know this isn't ideal, it does work and will get you through until we make adjustments to better support rounds with different numbers of exercises with in them.