The way I read it was 50% HP regained upon moving in, as part of the first instant tick. Which is...no.

Really I think the best way to boost Asylum is to give it the CU treatment of applying a HoT buff in addition to the field HoT. I wouldn't apply any healing from the HoT buff on the instant tick upon entering (the field buff could still do that) but still refresh its duration by doing so. I'd reduce the field potency to compensate so that standing in it keeps it where it is when factoring in both the field HoT and the buff HoT. It heals a lot as is, but the main reason the skill isn't as good as it could be is the fact it doesn't tick on you unless you're inside it for the whole duration. If you could get partial value out of it just for moving in and out or even being able to refresh the HoT before the field disappeared it would be far better.