Hm.. maybe the first statement (the one you quoted) was a bit cocksure. Else, I don't think i was saying anything that goes against these three points, but now that they're brought up, i feel i have some experiences which challenge them a bit.
The prospect of saving on song size
may differ from composition to composition, and from engine to engine. If you have a lot of songs and/or long songs, those volume columns just might add up and eat more space than a select number instruments played at varying amplitudes would.
It also depends on how varied your orchestration is throughout the total soundtrack. If you have lots and lots of instruments requiring lots of dynamic variation each, then that's a potential size problem. If instruments are reused between songs and channels, that's better. I think the trick here is to be sensible with what envelopes are needed to express your song(s). Some few of my instruments have 6-8 volume variations. Others have 1, 2 or 3. Echo variations are sometimes reused as other instruments for more quiet parts. Then again, by the sound of it, it seems i'm a bit more conservative than Kulor; listening to track 4 (classic). That one sounds daring and exiting and seems to explode sometimes in a way i rarely dare.
On drivers:
With pentlys' compromise, you kind of get the best slices out of two different pies. A lean volume column which greatly reduces the need of extra envelopes and instrument setups and offers some more creative freedom/convenience, albeit not as finely detailed as the native FT driver.
Another approach is having a hypothetical driver reuse parts the same envelopes by looking up different starting, looping and ending points in one long concatenated sequence; and maybe even jumping points if needed/rational. You can shave off a great deal of excess envelope data with some proper organization that way.
1. Tedious to use for that.
It's not as straightforward as simply using the volume column, i'll admit - but at the same time i wouldn't describe it as tedious. I find it rather easy, so it leads me to think this may be a different experience from person to person. I think what i do is that once i have the instruments set up, i just kind of automatically memorize what instrument number correlates to what volume setting.
Even so, it may be that i would've dared to be more dynamic with the use of a volume column for those songs i've written without one.
and fussing with a bunch of extra envelopes is not a very good substitute.
AFAIK, it's the only substitute short of a pently-style compromise, and the limitation it imposes is
1)mental - meaning you can rise above if you're intent on taking advantage of the full dynamic palette frequently.
2)size-oriented - which at least to some extent is circumstantial.
Then there's special cases. If you need cycle consistency, pubby's engine is the best option, and then you won't have volume columns.
In the end, at least it's an option, it's not too bad especially when you get used to it, and it just might be someones' cup of tea.