Like the Discus, my Lak 17 POH specifies a compass when cloud flying. Moreover, it stipulates that it must be compensated.

The standard “E2” type compass would meet this requirement, but is almost useless at normal gliding angles of bank. Slow though North, won’t go to South but flicks back. Only roughly right at E and W, if it catches up without lag.

In the UK we used to have a non-compensated compass, by Cook, that could be set to the bank angle and read true except for uncompensated errors. Far more useful, but does not meet the POH requirement,

Bohli can do it like the Cook compass – but I don’t know if Bohli can be compensated.

It is an impractical and almost useless legal requirement, imho.

I don’t know of any ramp check while in cloud, fortunately.

Chris N