Tanks don’t need healing pretty much. They also tank at the edge where no one should be really.
You dispel (not yourself pref) and then you only have one target to heal and if it’s yourself, that’s even easier.
Pillar responsibility can be offloaded on to other players. It’s not ideal if you do pillar and other people get dotted during that.
Spatial paradox can help with range during that overlap.
It’s not a fun boss to heal, but it’s not “difficult.”
There are several long range spells to heal far away targets: Rewind is 40 yards, Emerald Communion is even more pretty sure. There’s also aiming temporal anomaly.
Plus Echo is probably unlimited.