I use Blockada 5 and haven’t noticed any heating issues, it might be worth a go! I did have to enable most of the lists to get good coverage (and then a couple custom selected on/off over time) but I mostly don’t think about it after a little setup. The only thing I do have to worry about is swapping which VPN is on when I want a real VPN- but fortunately the VPN I like (Mullvad) has adblock built in too.
For android, the rdx app works great for occasional lurking