first of all I want to say THANK YOU for this great project! I installed /e/ on my old LG G3 and it is the best custom rom I ever had!
I would like to suggest a new supported device: The LG G6 [H870 H872 US997]
It is a metal unibody device and has good specs especially for its price. You can get a refurbished one for 159 Euro on eBay! I would like to see /e/ on the G6 because it is a good match and would improve my G6 a lot.
There is an UNOFFICIAL LineageOS 15.1 and also 16.0 and is maintained.