If I want the envelopes to not trigger when I use glissando, I’ll use ghost notes. Happens as of b7. I can make a file for demonstration purposes, but I think it’s fairly straightforward.
EDIT: I meant to post this in the beta testing forum, sorry about that.
It’s been this way since 2.8 and earlier, so the behaviour has not really changed.
If you want to reset/retrigger the envelopes during glides (or any other situation), you can use the 0Exx command where xx defines the envelope position from 00 to FF.
I disagree, Dblue, this behavior is something that did not exist from 2.8 to b6. I guess I’ll link a song that demonstrates it, but I don’t think I can re-obtain b6 to prove that it used to work.
I can tell you that the previous behavior is something I took advantage of a lot in my songs, though; the fact that volume envelopes reset even if you use Gxx unless you use ghost notes, which is what ghost notes are for anyway. I mean, it makes sense, doesn’t it?
As of now, I’ll use Exx as a workaround, so thanks for that, at least I can get back to finishing my songs from before b7.
And here’s what I’m talking about, with my reaction included:
https://dl.dropboxusercontent.com/u/28101589/Glissando%20retrigger%20example.xrns
Thank you for the demo song and hilarious commentary track… If only all demonstrations were that fun :]
Your 3.0 song obviously cannot be loaded into 2.8.2 any more, so I spent a few moments recreating the instrument and pattern in question, as best I could using 2.8.2 tech:
Note: I’ve trimmed and looped the sample just to save some upload space, and I’m also missing some of the plugins you’ve used, but the important stuff is still there and plays back just fine for the purposes of this demo.
4823 renoise-tilde-chip-glide-282.xrns
As you can hear, the note with glide does not have its envelope retriggered, and therefore remains silent since it has already completely faded out.
In this particular example, I think the F-4 0G10 could be replaced by E-4 0U10 to achieve the same overall result? Worth a shot, at least. I’ve included this as the second pattern in my demo, so you can check out how it sounds.
Digging a bit deeper… I tested your demo song in Renoise 3.0 b1, b2, b3, b4, b5, b6, b7 and b8 (whew!)
b1 through b5 all exhibit the same (correct) glide behaviour as Renoise 2.8.2 — ie. they do not retrigger the envelopes.
b6, however, does indeed (incorrectly) retrigger the envelope during the glide, as you have obviously found to be the case when working on your song recently.
b7 and b8 both revert to the old (correct) glide behaviour of not retriggering the envelopes.
The retrigger bug crept into b6, and was then fixed in b7, as you can see in this report:
Instrument envelope weirdness with GFF
Whaaaaat…I’m genuinely a little shocked by that. Modumanipulation is my jam, and somehow I got it in my head from this last song that that was always the regular behavior. It made complete sense to me, as Gxx was a pitch command and would be considered separate from the modulation envelopes, hence the existence of ghost notes.
I went ahead and used E00 to reset envelopes in relevant places, and noticed that it sounded oddly different from the b6 playback. For instance, it didn’t seem to glide the full one semitone to F that it did before, and putting a G00 a row below it actually helped it slide further, which didn’t seem right. Granted, this has to do with the instrument’s pitch LFO, but I couldn’t shake the feeling that it sounded different. It probably has to do with the way in which it was retriggering the envelope before as opposed to me using E00.
BUT : you’re totally right, as far as these particular patterns go, using Up/Down commands like E-4 0U10 instead of Glide commands pretty much knocks that concern out of the park. Although it does make me curious about why F-4 E00 0G10 sounds completely different from E-4 0U10. I do have more interesting examples that require glide, ones that come from the same song I pulled those patterns from, but in those, I can’t really notice any problems with the manual envelope reset. Thank you for jumping through all those hoops, testing this on all those versions.
Some Gxx related bugs have been resolved that might have altered the behavior. I thought this was mainly phrase related so far.
There were also some behaviors (not Gxx specifically) that were never right in the first place (never worked right in B5 and Renoise 2.8.x ) so these are corrected to work as intended as well.
So people adjusted to that wrong behavior will definitely notice it.
I don’t suppose there’d ever be an option or command to retain my preferred glide behavior.
OR WOULD THERE?
BE?
Create a song in Renoise 2.8, continue in compatibility mode in Renoise 3.0 
However some Renoise 3.0 specific features will not be available or fully effective.
As you can see from my post above, the preferred glide mode he’s referring to didn’t actually exist in 2.8, and was only briefly available as a bug in 3.0 beta 6.
Ewps, yes sorry, i’m not completely awake.