I would like to make workout shorter by editing same intervals, but dont see option how to delete interval, when workout opened. I tried to set duration at interval at 0 and refresh it and save it. But when i open it, its the same.
I don’t think that is - or should be - possible with a SMART workout. It has target intervals, whch will get shorter or longer if you under- or over- deliver on prescribed power.
Or something like that 
yes Robert, its like smart workouts work, but it doesnt mean that is should not be edited - e.g. instead of 3 intervals of 80%TP, having just 2 intervals with same intensity , easy interval with just 50%ltp can be skipped … I dont know of it just limitation for trials, but i found work around - I created new workout, and adjusted values as needed.
If you adjust any workout from the library, you will have to save it as a new - personal - workout. You can’t change Xert’s workouts.
Having said that, I’m not sure if you first have to save it to your personal library and then alter it, or if you can alter it and then save it. I think it’s the former…