Use Firefox browser instead of Chrome in Jitsi Meet Torture

I have sucessfully set up a load testing environment for Jitsi Meet using Jitsi Meet torture based on this tutorial.

Since the Chrome Driver is giving us troubles, I would like to switch to using Firefox on the nodes. I have provided the Gecko Driver and the sample node is displaying its Firefox capability on the hub.

Now when I launch a test run using the Malleus script, all users try to use Chrome and the output during startup says

[17] No participant type specified for prefix: web.participant1, will use Chrome...
[18] No participant type specified for prefix: web.participant2, will use Chrome...

How can I force Malleus to use Firefox, e.g. by specifying a participant profile? I cannot see any option to do that in the script. Any hint is appreciated.

[SOLVED] This is a classic case of self-answer. Shortly after reaching out to the community, we found a solution which I am posting here for everyone else to find.

Add these lines to the malleus.sh script for the desired number of participants:

mvn \
...
-Dweb.participant1.type=firefox \
-Dweb.participant2.type=firefox \
-Dweb.participant3.type=firefox \
-Dweb.participant4.type=firefox \
...
test

Of source this breaks the script dependency to the git repo source, but we could not find any other option. If there is one, happy to learn about it. For now we are happy it works!