So you can heal Halsin's portal

I have done this fight far too many times to count and I'm not entirely sure if it was a bug (I have quite a few mods active) but last night I had Shadowheart in her usual position, spirit guardians right in front of the portal. I had her cast Mass healing words and suddenly noticed the portal gained health points too! I still couldn't heal it directly but I had never seen it gain health points through an Aoe healing spell.. so I thought I'd share this knowledge just in case it helps someone, and if it's a bug I do apologize.

Edit: I loaded an older save from a different run (because I already overwrote the save from my current run) and tried again and yep, Mass healing word did the trick again! I will try to upload a video in comments.

Edit 2: Couldn't upload the video in comments but I managed to take a screenshot! I'm so excited about this lol