I'm a newer player so my suggestions may not be best.
The simplest solution without touching your build is Ageless Core Incarnate. It's the solution to many an end-hungry build.
On mobile and not able to really open mids, but there is room for end optimizations in the enhancement choices. For example, changing the to-hit IO in tactics with a Gaussian To-hit/end IO would decrease the upkeep cost for a slight decrease in to-hit bonus. The same can be applied to your other toggle skills with upkeep costs. Arctic Fog for example has quite a bit of an upkeep cost, iirc, and could benefit from more slots and enhancements that decrease the endurance cost.
Aside from that, make heavy use of heatloss, and carry blue inspirations, I guess.