I think you CAN vEverest on L’Alpe du Zwift and here is the WORKAROUND I am going to try
Since you can’t do a U-turn after you complete a ROUTE ( the exploit this bug was trying to fix ) then don’t do a route !
Instead start on Serpentine 8 but then manually turn left to the alpe and abandon the Serentine 8 route ( cleverly skipping the segment between the Mayan Bridge road and the alpe road ) and I think you are good to go after that with u-turns-a-plenty ( my new in-game name ! ) even after you pass the arch at the top since you will not have completed a route. Next just roll to the bottom and U-turn back up again 7.54 more times ! You could also do the Jungle Circuit counter clockwise and turn left onto the alpe road.
See the update
Game Update 1.18 - October 20th, 2021
@John_Blumenthal I’m afraid the 1.18.1 patch does not address the “U-Turn” issue. That doesn’t mean there isn’t a plan for resolving this issue …