Respawn Anchor PvP
I have heard from FitMC that the new meta for 1.16+ pvp may be the respawn anchors. As you can place then anywhere instead of only on obsidian like crystal aura. (you can decide if this should be Donor only or not).
Video where he mentions it can be found here: (starts at 9:43)
If you can find a way to use some of the features of crystal aura for detection and all that, but use the respawn anchor instead, that could be very op. The only other thing is to automatically fill it with glowstone before clicking on it for it to blow up AND to not have it only be placed on obsidian.
TLDR; Place anchor anywhere or near a player because pvp, fill it with some glowstone, then click on it like a bed. Automatically, fast, and efficiently.
while having good player detection