VLC (Snap) does not see files it should see

I migrated from Xubuntu 16.04LTS to 18.04LTS and one of the side effect was that I now must install VLC as a snap. I am new to snap and did some (limited) research. I understand snaps are confined, and I understand why it is a good thing. I believe the file in VLC source code that does the magic is https://github.com/videolan/vlc/blob/master/extras/package/snap/snapcraft.yaml

Problem is that as it stands, VLC is too confined.

• when I want to play an attachment from Thunderbird, it does not play.
• when I save the attachment to /tmp (which in my case is in RAM to avoid unnecessary write cycles to the SSD) and try to open it, VLC through the error "VLC is unable to open the MRL 'file:///tmp/msg0011.WAV'"

Can the snap be fixed so that a double-click in Thunderbird, or a double-click in the file browser (tested with Thunar and Dolphin) works as expected?

Unfortunately I do not know enough about snap to provide a patch (that I expect to be trivial for somebody who knows the snapcraft.yaml syntax) and I do not have time to learn about snap.

Thanks in advance,