It may be useful to ask a good question first:

What happens when you stop adding ferts and have an over grown/stable tank?
What is meant by a "stable tank"?

To the rate of plant growth that is?

It slows down.

What happens if you have less light?

It slows down.

What happens if you have less CO2?

It slows down.

It's not just ferts Vaughn, it's all 3.

The tank also might have plenty of reserves in the plants, or the roots, so a few days of no ferts might be fine.

You also might have enough organic matter built up in the sediment, much like an ADA aqua soil sediment that water column ferts are not needed.

If the tank is well shaded due to over growth, you also get less algae and issues, same deal with a non CO2 planted tank once it grows in.

Some tanks have more fish, they have a decent input of ferts from the fish waste, at least enough to prevent critical nutrient deficiencies.

So what would favor this senario you mention?

1. Less light first(is anyone on APC even bother to measure light?)
2. Less CO2/none at all/Excel(careful precise CO2 measurements? Think that this influences growth.nutrient demand?))
3. Rich sediment(how are they testing.accounting for this one I wonder?)
4. Low nutrient tolerant plants, some are much tougher under nutrient limiting conditions(say Anubias vs Eustralis)
5. Fish load/feeding(folks can feed far different than other folks)
6. Plant biomass differences
7. Temperature(cooler tanks have slower growth rates)

BTW, AF has hardly added any ferts to the 120 cm tank for a month, but it's loaded with sediment ferts. You can also reduce water changes without ill effects. But the tank does look nicer if you do the water changes and keep up on trimming and care. Folks get lazy is all.

But that's fine also, there's a trade off there.
It's not that it's some revelation.........or something like many seem to assume.

Not hardly.

You let things go for a bit and then hack and do some work to whip it back into shape again. If that's your goal, then use less light, ADA AS, cooler temps, higher fish loads, less nutrient demanding plant species, Excel only, etc.
Then you will have fewer issues and it'll be even easier to let things go.

I garden sometimes, but then I get side tracked, many do.
If you like a nice ADA style tank, trimming and gardening and ferts, water changes are part of the game.

If you seek no dosing, less work, more patience, no water changes at all, want to grow the tank in nicely and then have it be stable, why the hell not just go a non CO2 method or use Excel/low light?

All this stuff is already well known.
DW makes a good case for this in her book.
The other parameters influence growth and can do so dramatically or with varying degrees of intensity.

You need a starting point and light is the first one and then you go from there and look for CO2, then the relationship between light/CO2, then you go to nutrients ands WHERE the nutrients are and at what rates they are being added and what are all their sources, not just merely inorganic ferts and what you can measure with a 10 $ test kit and only in the water column.

You need to look at the entire system more carefully.
Where the nutrients are coming from, what determines the rates and cycling of the nutrients etc.

You end up make errors otherwise.

Regards,
Tom Barr