What's your progression level ratio with SS and VO2 Max?

Like a lot of people I seem to struggle with threshold workouts on the trainer. Last week I failed a level 4.5 and this week I struggled through 3 x 9minutes of 95/105% over-unders. But outside is a different story as a common workout I do is 25-27 min @ 105% (with a ~10 min active recovery in between). Other zones I can complete similar efforts both inside and outdoor, but I just seem to suck at indoor threshold workouts.

Anyway, that had me curious what other peoples indoor ratios are between threshold and the adjacent zones. Here’s where I currently sit

Sweet Spot : Threshold
2.1: 1

VO2 Max : Threshold
1.7 : 1