Game suggestion: Training grounds?

Hello everyone, I'm not sure where to post suggestions so ill just put it up here

What is this about?
This (the Training Grounds, (not related to Proving Grounds)) allows players to test their roster (squads and ships) against AI opponents, where players are able to customize their opponents (i.e. the character, gear/relic level, ability levels) under different battle conditions (i.e. GAC, TW, mainly omicron-based stuff) so players know how to use their characters / ships against certain opponents. This feature doesn't have to give out rewards otherwise people would just continuously use this feature.

Why is this needed?
Since CG has removed the Galactic Challenges, its not possible anymore for players to test their squads against AI enemies without certain restrictions (yes, players could replay journey guides, but their units will eventually be too strong and they can beat them in seconds, and they are restricted to certain factions). This feature would allow players to test their rosters like before, but in customized conditions to the player's liking.

Let me know if you (the community) like the idea or not, plus any additional suggestions to this.