So IMO preserver in pvp is lacking, not sure what plans there are at the moment, but here's basically what I gathered if it helps.
Sitting there inside Serenity and using Deluge-inundate-inundate with Natures Blessing on you works fantastic, you are doing reliable HPS and APS.
The problems are:
1) You need to be in Serenity, so when trying to heal a target.. well.. they move. If they aren't, you really notice, because Legendary Deluge is a huge APS and HPS boost when used every 3rd GCD while inside Serenity.
2) You can't put Nature's blessing on yourself, but to keep up with other healers at the moment in PVP, as it really is lacking, not sure if there could be a replacement in general to Nature's blessing? But you really notice the difference healing your target when they do have it.
3) You can't target swap without destroying your HPS and APS. If you use Deluge to get 5 stacks of instant blossoms.. well it goes on CD for 10s. So the only way to target swap without destroying your APS/HPS completely is a 3s channel Nurture before you can even properly heal because let's be real, Nurture does bugger all.
Would it be possible to program Serenity so that it moves with your target? It's vital that they stand in it.. or perhaps double the width of serenity, i'm not sure, but it's really small and needs to either be bigger or follow the target, it's imperative that they're in it if you really want to even try to keep them up.
I don't have anything for Nature's blessing other then be able to put it on yourself.. it's not as OP as divine favour, considering it has a 5s ICD? or 3s? I don't remember, so I think that's reasonable, and it can be Purged.
For Deluge, you really just need to make the Legendary a 2s CD without all the blossom stuff, it's a nice idea but the fact is that we use Deluge to target swap, and we can't now because we need it as a vital part of our healing rotation. This alone would fix many issues for preservers in PVP in my opinion.
Hope it helps/whats your thoughts. I do miss healing in PVP, DPS is getting pretty stale.