MATE PolicyKit for automounting in MATE doesn't work

[Lauristra]

This is probably more suitable in the Storage subforum, but this issue seems to be specific to the MATE desktop environment, so I'm posting this here.

I'm flawlessly setting up everything in my FreeBSD system thanks to the fantastic handbook, but I'm not having the same luck with automounting USB devices. I've followed everything as described in this section.

There's nothing wrong with it. I can mount my USB stick with mount without requiring special privileges and the automounting part works as well because media is mounted at /media, but the owner of the automounted devices is set to root and an ordinary user cannot write to or unmount it. I share my computer with non-technical users and I'm afraid I'll never be able to make them feel comfortable with using the command line.

So I did some research, and I've found many topics in this very forum covering it. Basically, I added the following to /usr/local/etc/PolicyKit/PolicyKit.conf:

<match action="org.freedesktop.hal.storage.mount-removable">
    <match user="myuser">
        <return result="yes"/>
    </match>
</match>
<match action="org.freedesktop.hal.storage.mount-fixed">
    <match user="myuser">
        <return result="yes"/>
    </match>
</match>

But this didn't work, and I set hald_enable="YES" in /etc/rc.conf. This is why I decided to post this in this subforum, because this doesn't work with MATE.

I've tried using other alternatives. I tried using sysutils/automount created by vermaden, but media can only be configured to be owned by a single user, I can't manage to get it to make it be owned by a group.

I tried DSBMC as well, but sometimes it freezes or doesn't detect any USB stick.

So, if I could get the PolicyKit configuration to work it would be great. But why isn't it working?
If it matters, I'm launching MATE using Slim, I'm using FreeBSD 12.1 RELEASE and my system's architechture is amd64.
Any assistance will be greatly appreciated.