Seconding Sway. I will admit I prefer autotiling (switching the split for new windows between horizontal/vertical automatically, rather than choosing which split you want), but overall Sway is so good in configuration that I still use it in spite of being a manual. The configuration takes time, but that’s common to pretty much any tiler.
I’d be curious what you mean by more control/customizability for sway/i3. I’m using niri now, and came from sway, and haven’t really notice a difference in capabilities (although niri has easier animations and the overview). And now I’m wondering if I just wasn’t using/understanding sway to the max.
I think on my multi-monitor setup, sway is maybe slightly better suited, but on my laptop I’m definitely preferring niri–but open to finding out new things about other wms that I missed.