In my opinion 15 energy per match is a bit high.I personally explore 3 difficulties of EQ (Master, UC and Cavalier) every month, mostly for the titles and the extra 4* shards for iso.Reducing the weekly objective from a total of 30 wins to a total of 18 wins (instead of 5 wins per milestone 3), or reducing energy requirement to play a match to 10, would be a good quality of life change and save the mode from being a time and energy drainer, that is needed to do other modes or content.
‘Full of bugs’ is a bit of a stretch.