Slow connections optimize

Are there any “advanced” (conditional) configuration options e.g. for video quality?
I am aware of options like constraints - video - max, but AFAIK it’s global for every client.
Is e.g. possible to set, that rule will be used only if the count of participants will be higher >5 persons, but will be without limit e.g. for 2 participants?

If there are any best practices usable in this “COVID-time”, I would appreciate them. Also tips for your favorite plug-ins, additional tools working with Jitsi.

Thanks in advance for any relevant comments.