Yes Dune space navigators did overcoming hughe distances but where using a known theory by folding space describd by the Holzman effect.
That is valid. The network has to be disabled before WNMHGB. if it existed, bypass the galactic barrier with a short jump.
VOY already was a joke given TNG and TOS journeying outside the galaxy.
Sure, but the fact that the technology is very hard to use and even harder to replicate unless you REALLY know what you're doing makes the spore drive a problem that basically solves itself. Given the problems we're already having with stamets, the "Mirror Universe" mishap, and the Galactic Titty Twister that killed the Glenn, it's already kind of obvious that this drive will never go into mass production.
Given that the Romulans gave up on the phasing cloak for less, I'd say this is probably true.
Gimmicky ways of getting "outside the galaxy" isn't the same as having to travel by regular means through the Delta Quadrant.
Enterprise in TOS did it without gimmicks.
Like when? They've gone in the galactic barrier, and aliens took them through it once, but everything that I know about is gimmicky to me.
"Where No Man Has Gone Before" is just the Enterprise traveling through the galactic barrier.
Doesn't the Enterprise suffer heavy damage after flying into it? It's not like the ship just ventures on out of the galaxy ho hum like everything is normal.
Yes, and it's possible to do it again. The larger point being that they got to the edge of the galaxy unaided and had time to get back to Federation space. Not exactly slow speed there.
I'm guessing the mycelial network somehow becomes unavailable to them -- either due to something like you suggested, or it simply "breaks".
In "By Any Other Name" the ship goes through the barrier to take the Kelvans back to the Andromeda Galaxy, but without suffering any major damage.
