I now have enough data to ditch the test. I know when it's time to stretch an interval's duration or pull some duration and add wattage.
The 3x3min getting easy? Either add 10w or stretch them to 3:30 or 4:00 pursuits.
I'm now doing my old 3x3min's for 4 minutes. I'm about to cut duration and add watts.
Same for my 3x10's. If I nail another 3x10, it'll go to 3x12.........then 3x9 with over/unders at more watts.
Same for SS. I was at 3x15 at a power a month ago, now up to 2x20. Next 1x40 and/or 1x60. Then back to 3x15 at 10w more.
Or.......subtract XXw for TT bike on same workout. Lol.