accel-ppp supports weight and backup attributes when configuring RADIUS servers
https://docs.accel-ppp.org/configuration/radius.html
but VyOS can't currently configure them (at least for L2TP server, which is where I need them)
https://github.com/vyos/vyos-1x/blob/d4f9d6ce726ea4d4fff6eecc16678d7a45a0b555/data/templates/accel-ppp/l2tp.config.j2#L94

I would like to see settings such as these:

set vpn l2tp remote-access authentication radius server 192.0.2.1 weight X
set vpn l2tp remote-access authentication radius server 192.0.2.1 backup