Cycling Resistance Field in Record Message

For quite some time, GC for the Web had been charting the values it found in field ID 10 (Resistance) of the Record messages. The field remains defined in SDK 21.133, but the values are no longer being graphed when viewing the activity. Has anyone heard any scuttlebutt about a new [undocumented] field in the Record message, or perhaps there's another newer message that TACX and/or Zwift uses instead?  Maybe Garmin decided nobody was looking at graphs of it as part of their user-interface re-engineering? The graphs didn't seem to vanish when the Zwift interface went live, but the timing might indicate more than coincidence. The FIT (for a stationary bike activity) uploads just fine, the field just appears to now be ignored. If anyone knows of a [recent] TACX FIT file I could examine for reference, that would be *huge*.  Thanks!