Question about EOMA68 Libre Tea Computer Card (RYF)

Hi

If you are not familiar with the product,please look down below.
https://www.crowdsupply.com/eoma68/micro-desktop

I never used to own arm in miniPC form (except for non usable android phones).I thought that it would be a good idea to switch my off job computing(personal development)to total libre computing platform.
Now i never bought none of RYF laptops provided by GNU.org,simply they are old laptops that corroded long time ago(my opinion at least) and this is first time that we have a chance to have new manufactured RYF certified PC.

I am interested in web development with accent on JS(besides html/html5 and css/css3) and interested in performance of the components inside the board.I done various software in GUI game engines and didn't wanted to make mistake when deciding on code that i will spent most of my time on.I decided to go with web option simply because there are more than 1 runner for the code and more than 1 platform that more than 1 runner can be run on.

If MALI GPU opensource driver is not available in Libre Tea Computer Card how much would i be able to get on the performance?Now my target resolution would be half of the fullHD(960x540)for the JS games running in Canvas2D or WebGL(2D games mainly)with 30FPS.

Also if we do have only microSD card as an option how much would speed be degraded compared to eMMC chip or something similar?

Regards and have a nice day ;)