I believe George and Steve said it was cooked more(ADA AS II vs ADA AS I) which I take to imply why it had less effect on the tap water interactions, and why it would be more crumbly.
There's balance between too soft(mud) and not soft enough(ADA AS II).
I know Jeff does not like the ADA AS II and has had customers complaining about it as have other folks. I've never found too much wrong with ADA As after the first 2 months.
It can vary batch to batch, you might have to do a lot more water changes with some, less with others.
Once it settles down, things go pretty well.
I add fish and shrimp is less than a week, typically 3 days, but I do frequent water changes and have plenty of plants from day one.
I do not think it's stated anywhere that we should wait any amount of time prior to adding fish.
I've not lost any fish either.
Just like ANY new aquarium, for the first 1-2 months, you are going to do more work and water changes till things settle in and the bacteria are established.
This has nothing to do with NH4 vs say NO3 and "helping plants"
This is a bacterial issue. NH4 keeps leaching however the bacteria are easily able to mitigate that after 4-8 weeks.
You can add NH4 to a plain sand tank vs say NO3 and see these differences specifically, but if you allow bacteria to grow and prosper, you really cannot possibly tease apart what fraction of NH4 is going to plants and if it really helps at this stage than say NO3.
You can claim it till you are blue, so can ADA, but you/ADA have not shown it. It's speculatory. We can see this issue clearly in fish only tanks and time frame is curiously similar.
We can also see it if we add NO3 vs NH4.
And we can also add peat etc.
Maybe they are correct, but I've not seen evidence that suggest that it is.........and I've never seen enough differences using NH4 vs NO3 to suggest it really makes a difference an aquarist might see due to that issue alone.
Plants grow extremely well on NO3 and some small amount of fish waste. Adding more fish tends to reduce growth/lowers O2 near as I can tell, so that would suggest the NH4 is not the main issue here.
I think it's much more like fishless cycling............and much less with any type of form of N that "helps the plants" more.
PS is loaded with NO3 anyway.