Since you asking for suggestions, mine is to make clan war more prevalent even in the "casual games" to at least alert people that clan wars are currently going on. finding cws is annoying enough by having to join rooms/lobbies and asking for cw. announce when people go up in cw's in the general chat as well as show a clan war queue when clans are active to incentivize activity in clanwar channels
https://i.imgur.com/czbT8ny.png
You could also add something like this to the forum next to the events ingame panel.
Secondly, cw streaks should be rewarded as well as possibly even breaking streaks. X amount of streaks should give you something like a few lucky boxes or cosmetic boxes.
Clan warring could also accelerate your activity points / time online, for example cwing 3 times a day = 1 hour, 6 times a day = 2, 9 times = 3 hours (numbers obviously adjustable).
Can't think of much else but do with this what you will lol