Finally overflew a VOR today (only once in 8 hours flying! Navigation ain't what it used to be), at FL380.
The deviation bar started wavering noticeably at about 9/10 miles, then disappeared completely together with the TO sign at 7.2 DME slant range. For a period of about 20/25 seconds, except for the occasional flicker the deviation bar and VOR pointer remained out of sight (interestingly this happened absolutely simultaneously with the standby RMI's VOR flag appearing, and I'm sure the FMC has no input there).
At approximately 7.2 DME outbound the deviation bar reappeared (wavering wildly at first, then steadying), together with the VOR pointer and a FROM sign.
Based on this I'm completely convinced the presentation is 100% raw data. Having said that there are more customer options on a Boeing than you can shake a stick at, perhaps it's an optional feature?
MD