Interesting strategy mate. I definitely use all means necessary to maximize my energy throughout the season. Typically I will open the first batch of all three loot chests and then run the Xbot on wild to use up all the excess energy. This huge rating boost early on is enough to sustain my account in the wild leaderboard for the rest of the season.
After the initial surge of battles in Wild, I spend the rest of the season battling in Modern trying to get back to Champion 1. Sadly, my win rate is not good or consistent enough to reach Champion 1 anymore, but in a good season I can manage to make 4000 rating for Champion 2.
This strategy is very functional and seems to be working for you. I currently only play Wild because I don't like limiting the use of my cards