Not true at all. I did Lamarck and it was fine.
Intervals were completed as: 98.5%/100%/101%/101%.
(Note that I was exactly mid-way between ramp tests, and the latter ramp bumped me by only 5%.)
I find it a bit odd that so many TR users find so many workouts so painful. 
The TR logic re: Sweet Spot is:
Sweet Spot work is specifically aimed at improving your ability to resist fatigue at reasonably high power outputs over substantial lengths of time
The TR SSB plans do not evolve a great deal in either power or duration. The first workout in SSBHV1 is 3x12 w/ 3min recoveries (36min on, 6min off; 6on/1off). The last workout in SSBHV2 is 8x9min w/ 2min+7min recoveries (72min on, 29min off; 2.5on/1off).
Yes, the total duration may have doubled, but the interval lengths are shorter and the rest time almost quintuples! The TR plans are not progressing toward “substantial lengths of time”.
You need both.
There is a 'UGE difference between doing 8x9min intervals w/ 30minutes(!!!) of rest vs a 1x72min interval with 0min of rest. Doing the short intervals does not overly improve “your ability to resist fatigue”, esp. when your muscles are getting so much rest. Every interval shouldn’t be done daisy fresh.
It’s the same thing the guys talked about on the podcast re: Z2 work – it takes a long time to exhaust those resources so those unique adaptations can take place. You’re never going to reach even close to an exhaustive state, esp. in sweet spot, by doing shrimpy interval lengths and NEVER extending duration.
I couldn’t imagine being a multi-year TR user and choosing to do the same 10-20min SS intervals year after year. 
You can hear me now and believe me later, or take it straight from the Taskmaster himself:
