It’s nuanced. Here’s a breakdown of what the current situation is (to the best of my current understanding).
- Workouts completed in a stock plan will give credit to Progression Levels.
- Workouts in Plan Builder will give credit to Progression Levels.
- Workouts completed in a stock plan will not trigger future adaptations.
- Workouts in Plan Builder will trigger future adaptations.
- Outside Trainer Road workouts may or may not work for you based on a couple factors, namely the head unit you use, and even then they may or may not be classified correctly once completed. These are listed in the Known Issues and are a current priority for the TR team from what @IvyAudrain has mentioned.
- Outside rides like group rides or anything that doesn’t have the strict structure of a workout currently will not adjust your Progression Levels or provide credit towards future adaptations. This is also one of the TR team’s near-future if not current priorities.
My suggestion in your case is to just set up Plan Builder with an end date for your 2021 riding season to get the adaptations. You don’t need an A or B race to do this at all, so you can set it up kind of free form and add in events like gran fondos or other organized rides as if they were your A, B and C events down the line and PB will adjust your plan when you add them.