Support Volunteers can't make changes to Firefox and the developers do not directly monitor this site. To submit suggestions for new or changed features, may I suggest:

Feedback: https://qsurvey.mozilla.com/s3/FirefoxInput/ Facebook: https://www.facebook.com/Firefox Reddit: https://www.reddit.com/r/firefox/ Twitter: https://twitter.com/firefox

There also is a forum run by the Add-ons team where you may see talk about potential future capabilities of extensions to modify the UI (initially limited to colors, I think, but perhaps more down the road): https://discourse.mozilla-community.org/c/add-ons

Please let us know if this solved your issue or if need further assistance.

Thanks for the Info and the links.

There will only be minor changes to the new design and they will take months, so users need to take it into their own hands to modify the appearance for now. Do you have a wish list of what specific things you would like to change?

I want, when an upgrade happens, that my current layout is preserved.

Amazing description of what you want....