So being unable to get any powdered MHRB, I ended up with 500g of shredded bark which I hadn't used for extractions before.

I figured before doing a large extraction I should do some tests and I did took two 30g samples of the bark to extract side-by-side.

I chose Q21Q21 limetek with lime and vinegar which naturally I've done many times before for one 30g batch
For the other I chose Marsofold's A/B with Lye and vinegar, which it was my first time trying.

Q21Q21 tek on 30g shredded MHRB

RESULTS:
Pull 1 @ ~3 hours for very start of tek combined with Pull 2 @ ~72 hours.


(note the quarter)

Marsofold's tek on 30g shredded MHRB

RESULTS
Pull 2 @ ~72 hours


(same quarter underneath)

Pull 1 @ ~3 hours for very start of tek (very zoomed, no quarter)




Personally I recommend doing a lye tek if you can only get shredded bark. I've tried 3 experiments on MHRB without having powdered MHRB (2x with resin, 1x with shredded) and none of them gave any satisfactory yield.