Jbinmages limit for specific roles

We want to limit the upload of images for different roles according to:
https://github.com/pkp/pkp-lib/issues/1096
However, we want to use it in both OCS and OJS. And as it is now our OJS is unfortunately down. So we started with OCS.

We have found that

Validation::isSiteAdmin()

works well in OCS.

However,

Validation::isConferenceManager()

does not work.
I found in Validation.inc.php that this function ask for a $conferenceID which I guess is not found here.
When I tried to hardcode it to a specific conference it works

Validation::isConferenceManager(6)

Is this a bug or is it possible to code it so that all conference managers in any conference have access to upload a big file?

I am thankful for fast answers!

**Update: **
In Request.inc.php:77-81 it states that the function getConference() is deprecated! Could that be a hint?