Li Shenron
Legend
Ok, that's interesting. Sounds like basically the main design purpose of the long jungle crawl is to level up characters, but I have an odd approach to levelling up and choosing adventures: since I don't like adventures designed to span many levels*, I usually start an adventure when the characters are already at mid-levels if not near the levels expected to finish such adventure. If I read it right, ToA is designed from level 1 to 11, which is way too long for my tastes (I am more used to older editions adventures spanning 2-3 levels), so I would be looking to start it with the characters at least of level 5. With my approach, obviously the first part of any adventure is always easy and the second part gets harder, but this is how I like them to be, rather than scaled up but mostly equally difficult start-to-finish. Maybe in ToA starting at higher level would also help moving faster through the boring jungle crawl, but not necessarily as even easy combats can be time-consuming, so it would be more a matter of avoiding them or being able to end them quickly. I would be more concerned about missing that good "random stuff", but perhaps the DM can just choose to make the PCs stumble upon the interesting one.I own and have read ToA, and chose not to run it.
It would depend on how you handled levelling. You could skip through it quite quickly, but you would either need to level the party very quickly or start at a higher level. And there is some random stuff scattered around in the jungle that you would miss out on. One thing I would never do it let the dice completely dictate the encounters - it would be quite easy for the PCs to encounter something of completely unsuitable level and get annihilated!
*technically, my utopic campaign is many adventures that run in parallel, in which case I wouldn't mind each of them to span lots of levels, but in reality I can only really afford to run serial adventures
Overall it sounds like ToA roadmap could be summarized as Jungle -> Temple -> Dungeon -> BBEG. From a story point of view that's something that by my personal tastes shouldn't even require to level up once, but of course at WotC they want to cover as many levels as possible so that the players are using a larger portion of the character material (and feel like they need to buy another book soon).