F12 Boot menu delay too short, PVEMUser cannot change boot order...

Hello,

i'm using Proxmox where users have individual permission "PVEMUser" for individual VMs
This permission does not allow change boot order in menu Options=>Boot order (which i think you should have allowed by default for for PVEMUser permission..)

So user then have still option to use F12 menu. Problem is that delay for menu is very short, i think 1 or 2 sec
There is no chance to chatch pressing F12 key when machine is turned on (console has to be opened, than Java varning etc..) So only option is catch it in the moment in restart, but it is not easy also...

Is there any option how to make delay for F12 boot menu longer, for example 10sec ?

Regards
RH