8.1.4, as you've probably realized is an End of Support version.
This will also be limited by the amount of hard drives supported by the HA pair.
This detail is expressed in Hardware Universe.
This was pulled using the closest version we have available within the HWU site.
You could conceivably have All but 3-6 of those drives (used for the root aggregate(s)) for one large data aggregate.
My apology, this does not tell us the maximum aggregate limit. We already look at it for before.
Unfortunately this is not the right information.
I am not sure you are posting answer and confirm what your write is acceptable and trying to claim something??... I won't be accepting something that is not giving us right direction just for the seek of getting points as member of something.
The information you're looking for can be found in some of the older documentation, as this is a significantly older system:
Because the limits you're looking for are not Hardware specific, Hardware universe is probably not going to be your best bet for that detail.
I agree, there is no information in hwu/official netapp site. Rather, if I search internet then l come across this link which mentions it.
If you look on HWU, there is a supported RAID config. It tells you that you can only have 20 SATA/NL-SAS (FSAS) drives per raid group. You'll have to create a new RG with 2 parity drives.