Update time!
I thought I could edit the post and add the update right in, but looks like editing is time-limited. @Nathan, if this is a setting, how would you feel about changing it to allow edits permanently?
I continued to move around the drying powder every now and then.
As the water content declined, it started to form clumps, which could be easily broken apart again for the most part when they dried out further.

On the fourth day after setting it out to dry, it appeared to be dry enough to grind it again in the mortar.

It was quite ok to remove the frankincense from the plate, though some scrubbing was needed. I used a tiny piece of metal mesh as a scrubber at the end, which worked nicely. At least the scrubbing results in very fine powder. 😉

Grinding the powder up again took longer than I was expecting. It needed a couple of rounds of grinding and sifting and eventually, I was again left with a teeny tiny rest that wouldn't grind.


The dry powder was 27,7g of about 45g so about 62%, meaning it "lost" 38% wight from removing the gum.
That's not a bad yield! (Especially if you use the frankincense gum water.)
I soon realized that the powder wasn't as free flowing as Nathan described. So there must have been some remaining moisture.

I took a wile until I came to grind it again. It was more a braking the lumps then grinding, actually. I had it sit in the open for another half day after that, and now it seems to stay powdery.

Nathan did a blend of 30% washed frank with Sandalwood, so I did the same. I used the Australian sandalwood I got from Dave @TheWorldMakesScents because I think this is what Nathan used as well.
I burned it right away as a trail.
I found the frankincense note pretty strong and churchy, and not very refined. Burning it again now, it appears that the frankincense in it has mellowed, as I smell the sandalwood much stronger (and more pleasant) today. Nevertheless, it's not what I would aim for. But the Aus. Sandalwood might just not be the best companion for this Frankincense, at least for my nose.

Heating the washed frank is really interesting.
Bonnie @EspritDeLaNature told me what she loves about this certain Frankincense is a floral note. I understood what she meant, but wouldn't have called it floral. Now, in the washed version, I totally get it.
Overall, I'm very surprised how potent this powder still smells. I was worried about losing potency, especially as it smelled so strong while drying. But actually, it almost appears to be stronger smelling than before.
Comparing the unprocessed, powdered Frank with the washed one (using my tealight heater):
Unprocessed: Typically frankincense, slightly tart, a lot of fresh notes, citrusy, pine-y, slightly camphorous, Subtle sweetness. A very full, round and complex profile.
Washed: More intense in a way, more resinous, sharper in its freshness but less pine-y. Floral.
I get more sweetness from the unprocessed Frank, and it gives a softer feel, but at the same time more tart notes. It's rounder in a way, warmer, but the washed one is refined, clearer.
Comparing both on charcoal, the unprocessed powder turns acred almost instantly; the washed one gives a sharp resinous and citrusy/pine-y smell. It's gone notably faster than the unprocessed frank.
I thought I would have come to do more experiments with it by now. I will post another update once I played around with it a bit.
TLDR
INFO BUBBLE
Approx. 45g of B. sacra - ground to fine powder
Approx. 450ml water (boiled, cooled down tap water)
3 days of macerating, daily stirring (room temp)
2 more days of macerating, giving the fines the chance to settle
(make ice cubes from the frankincense water to enjoy as a delicious drink)
drying solids on glazed plate
_
About 4-5 days total drying time
Grinding and sifting once more
Yield: 27,7g= ~ 62%
Potent smell; didn't lose its character at all but still notably different to before.