Thanks, I think it´s helping a bit. However, it´s still lagging / fps dropping. I did some tests and I´m 99% about the problem:
YEP_CoreEngine
If Yanfly´s core engine plugin is active together with the minimap then it´s resulting in fps drops. At least for browser deployment and no "high end computers".
If only one of them is active, then no problem. I did change a lot plugin parameters in minimap and Yanfly plugin, but nothing was working.
EDIT: Problem has been fixed in a new version of the Minimap. Thanks to the awesome developer Aerosys!