Thinking of Benahmed's suggestion: https://lalescu.ro/liviu/fet/forum/index.php?topic=6831.0 , I thought of a possible improvement, allowing to change the order of activities in the activities list; also, we could just remove or add one or more subactivities from a group of activities.
I am not sure if it is very difficult/complicated. I did not think thoroughly of the implementation. The reason is the lack of financial support for FET. If we have sponsorship offers, I will consider doing this.