Please don't. Up to the Challenge sucks. It equates to less than 20 hp/s at the hp cap.* That is not better than an on-demand heal, idiosyncratic as it is. Moving it to the self-rez (a Lv28 pick) with a 90s cd—50% longer—and forcing us to take every single power in the set to be viable is a gargantuan quality of life reduction.
Not to mention, the set already has a passive regeneration power—called Fast Healing. Why double up with redundant functionality instead of just buffing values on FH? It does exactly the same thing.
If you *MUST* do this, please just add a mutually exclusive option instead.
The only change Stalker WP feels like it needs is some analog of Quick Recovery rolled into one of its passives, akin to Rad and Bio's. Adding another toggle, without the help of some +Recovery (a hallmark of regular WP) is the most baffling direction to go here.
*Based on Mids. Currently cannot slot anything into UttC on beta. That said, Mids is confusing because the power info claims <19/s, but when subtracted from totals looks more like ~33/s. This is on both Sentinel and Scrapper. Even if it's the higher number, that's only equivalent to about 3 stacks of RttC. Which is awful because Scrap, Brute and Tank still get the proposed Resurgence and higher MaxHP.