There are some unusual cases in which FET was put to work, with some little customizations, and it seems that the results were good. The idea is to allocate activities to slots, in which FET days may be for instance real teachers, or other tricks.
I will list here some of these custom versions:
1) Dolphins to patients scheduling: https://lalescu.ro/liviu/fet/forum/index.php?topic=1782.0
2) Scheduling students to teachers: https://lalescu.ro/liviu/fet/forum/index.php?topic=3961.0
3) Automated activity planning: https://lalescu.ro/liviu/fet/forum/index.php?topic=4066.0
Maybe also in your case we could develop some similar tricks. I invite you to post your problem on the public forum.