Average steepness means there are steeper sections which could, very rarely, fail and trigger the slope.
again,it'sgenerally hard to trigger a persitent weaklayer buried 150+, unless you get a shallow point for triggering. Deep but variable snowpack is hard to define. Does it mean that the weakest spot on the slope is 150cm above the persistent WL, and the rest of the slope deeper. Or does it mean that the average HST above the WL is 150, and sign. shallower spots around them.
Not sure how a 20 degree slope with mature timber can require full commitment or can have a serious terrain trap.
I'm assuming mature timber, staying out of glades
likely peak activity has passed but is still possible
chances of triggering are less because of the depth of the weakness and the mature timber
if I decided to ski this type of terrain in this given situation, 1:1000 chance...
easy skier triggering is coming as the slab settles. Being in mature timber and a relatively gentle slope will help decrease the frequency of triggering
I'd say it is trending toward 1 in 10 as rain continues and with cross-loading of the slope there may be a shallow trigger point that will get hit
depth of weak layer MAY be an advantage but rapid warming are a key flag
new snow + rain, HST avalanche much higher chance, deep slab, maybe less  likley.
Generally I wouldn't expect a slope with mature timber to be able to produce 50x50m slabs, but since it can the odds go up.
slope angle is the key factor for me
Less than 20 degrees makes it unlikely even though the condition may be touchy
Slope angle again. Unlikely

Event is highly unlikely, but would have serious consequences. Avalanche would move slowly however.
Highly unlikely event, but serious consequence.
Steep slope into a terrain trap, deep fracture, it does not look good for you if it goes
given amount of  snow in a deep slab i looks bad
size of the slope is the only favorable thing
no options and a t trap
Could be a long ride with a deep slab

By all at once, I mean spread out with partners through the forest. I would put multiple skiers on that slope, but not all at once.
Spaced out, not necessarily one at a time
Often in situations like this I use ski cutting to remove the snow on a steep small pitch and ski the group down on the bed surface.
hard to say one way or other without seeing the terrain, perhaps a small group would be fine, pehaps I wouldn't go at all
With professionals, maybe subject to easy escape at decision points,  but most likely not given load and rising temps
Terrain trap at the bottom is a key issue or unfavorable outcome so No I don't want to go there, given rapid rise in temp and a wek snowpack
see the rain comment, maybe I'm conservative?  given signs no thanks
rapid warming steep slope with a terrain trap, sorry no thanks
terrain trap make me feel apprehensive about this,perhaps I could manage it with good control?
Despite my assessment of this problem avalanches are not that likely on such a low slope angle but I have seen them.. this week
High consequence, recent activity