Greetings!
New STR-DG1100 receiver with RM-AAP018 remote.
I'd like to change the AV command mode of my system to AV1 so that I can use universal remotes such as RM-V302 which are nice and simple and work well with the cable box.

Works as expected on the receiver side, and the RM-V302 then controls the receiver just fine. But the RM-AAP018 side does not work at all.
Instructions in the manual are:

1) Press I/O (power) while holding RM SETUP button
2) RM SETUP BUTTON flashes
3) Press 1 or 2 while the RM SETUP BUTTON is flashing
4) Press ENTER when the RM SETUP button lights up.
5) RM SETUP button flashes twice, completing the setup.

Step (4) never happens (RM SETUP continues to flash, as if it misses the 1-press), and when pressing ENTER, the RM SETUP button flashes 5 times.

Alternately, if I could set the RM-V302 to AV2, this would work too. But setting that remote to Sony receiver code 002 doesn't work with the receiver in AV2 mode.

Is there a solution? Perhaps a more modern Sony universal remote?

Many thanks in advance.