Xert is at a disadvantage with a 30-day trial. There’s much to learn about what’s different and why then apply it. That takes longer than four weeks. 
Here’s my all-indoor 120 day experiment with Xert from a couple years back –
Pre-Base to TED; 120+ days; 100% recommended workouts completed at 100% difficulty
One thing to note is I started with a TL of less than 30 (1 star) and progressed to 100 (3 stars) by my imaginary TED. Then I rode up to 15 hours/week (4 stars) during the summer because I could.
Increasing TL over time and your ability to complete any plan is going to be the key contributor to fitness gains. The maximum hours you can invest will also affect the types of workouts you choose to do. Xert provides a set of guidelines to follow but you decide what to do within that framework.
Academy series videos are the quickest way to get up to speed – Discover + Improve + Perform
FAQs here – Support Home – Xert