It's confirmed to be working, but I doubt it's working with Opo the way it works with Find 7a.
I bet your Note 3 charger charges OPO at the same rate/time that Find 7a charger does.
The Find 7a charger utilizes 7 pins vs the 5 pin standard for the micro USB.
This was found to exist in both the Find 7a and OPO (Reviewed Samples).
Though Carl stated on reddit that the production model will not have the special "7 pins", the sampled OPO devices did and was shown in a teardown.
So for one, the Note 3 charger is distinctly different than the Find 7a charger.
And two, though the sample OPO devices may have 7 pins, the production models may not.
Just hoping that the production models have 7 pins to utilize the rapid charge feature.
EDIT:
Actually it's 4.5A, but based on OP info (1%/min charge rate) I think Opo is limited to something about 2A/hour. Probably a 2A charger will charge at the same rate as Find 7 charger (4.5A).
My S4 can fast charge up to 1.9A/hour. So in an hour and half I have full battery.
It has 7 pins, not 5 as standard micro USB.
You've also stated that it has 7 pins previously, not sure how you concluded that the Note 3 charger is identical to the Find 7a's