This is all preliminary, of course, but I was talking with my brother earlier and just conducting thought experiments on which Jiggies would be best to skip. Here's what we came up with:
MAYAHEM TEMPLE (0)
None
GLITTER GULCH MINE (1)
Ordnance Storage (it's out of the way a little, you never use Beak Bayonet again, and I can't strafe for shit

)
WITCHYWORLD (5)
This is a tricky one. A lot of Jiggies in this world require Mumbo, but he takes a long time to get and for the Dodgem Dome you need to get the van again. We went for skipping the whole lot.
Saucer of Peril
Dodgem Dome
Star Spinner
Top of the Inferno
Boggy's kids
This means doing Mr. Patch D:.
JOLLY ROGER'S LAGOON (0)
None, which means this level is going to require two trips thanks to Hatch. I might still skip that, but then I'd have to work out what to change it for.
TERRYDACTYLAND (4)
Oogle Boogles
1 Jinjo unlocked via the big T-Rex (this, combined with the next, enables me to not bother with Mumbo at all)
Styracosaurus family
Terry's eggs
GRUNTY INDUSTRIES (4)
Weldar (single segment, remember)
Six rabbits
Clinker's Cavern
Quality Control (again, skipping Mumbo, and the washing machine too)
HAILFIRE PEAKS (3)
Chilli Billi + Chilly Willy
Alien family
Sabreman
CLOUD CUCKOOLAND (3)
Canary Mary (thank goodness!)
Mr. Fit
1984 safe
Just for the record, this means still having to do Jiggies like:
Mayan / Colosseum Kickball
Rocknuts tribe
Ice train station
The Shack Pack Jiggy past the Weldar Jiggy in GI, even though you don't get Weldar's Jiggy
Interestingly, I ran a timing on Dragorn's Ordnance Storage run and the marginal time it took him to do that was only 2:39, which surprised me quite a bit. Having said that, it's fair to say I wouldn't be able to match that - the whole 45 degree strafing thing is gonna take a ton of practice.
This doesn't yet consider which notes or Glowbos to skip, and depending which levels have to be revisited things might change. (An example I already gave: if I have to go back to JRL just for the Tiptup Jiggy, then I have to find an efficient way there (perhaps through HFP, it has no train station of course) and add the time taken to get there to the time spent in JRL to get the actual Jiggy to work out marginal time.)
Essentia: That trick is NTSC only
