I use mainly Cyberfox / sometimes Firefox Quantum and would like to know is there a way to change the size of icons in menu bar...as they are small due my not so good vision.

I have tried various customising Firefox add ons but without success as some extensions don't work or not compatible or ceased to be updated especially with Firefox Quantum due their change of policy regarding 3rd part
extensions.

Does icon size on menu bar depend on basically how they are designed by developers and you're stuck with the size ?

I have a 19 inch HP Pavillion monitor set to 1600 x 900 not the native recommended of 1920 x 1080 as everything is even smaller and set text size to 125%.

Thank you