Could a pilot navigate using distances and radials from an RNAV waypoint, similar to VOR navigation?
In a modern B737 (NG/MAX) (and probably most other comparable aircraft), this is trivial. The simplest (and most realistic option for an emergency turn procedure) would be to fly the procedure in HDG SEL:


Enter FOBAR on FIX page
Add a 2 nm range ring for FOBAR on the FIX page. This ring will be displayed on the ND (Navigation Display)
Add the 90 radial for FOBAR on the FIX page. This radial will be displayed on the ND.
Fly the procedure in HDG SEL, monitoring the ND.