So I dug into this a bit last night on a workout. While only an hour, virtually every post in this thread shows drift by the 40ish minute marker, so I figured I’d at least see something there. Short version: Zero drift during the test (Slide Mountain -2)
Here’s the data set: https://analyze.dcrainmaker.com/#/public/0ff220a8-9975-4947-63d3-1260595d82ac
Setting aside the complete dropout festival that happened between the SRM X and FR745 on the first interval, or that it was oddly lower than the rest - there was zero drifting differences between the KICKRv5 and the Quarq DZero, or even the SRM-X (again, ignoring the dropouts/offset).
For this test I did no warm-up and no calibration of any units, nor did I ever stop pedaling (as to not give the KICKR a chance to auto re-cal). From a gearing standpoint I was small ring up front, and almost the easiest ring on the back. Temperature in the DCR Studio was constant, at about 73F/23C according to the Edge device on the table. This is on the latest production V5 firmware.