Unsolved Recalbox PC, edit GRUB, load image during boot?

[mundodisco]

Hi everyone,
I have installed Recalbox 6.1.1 on a Raspberry Pi 3b and on a Dell desktop PC, both with "Alekfull-Bello Cobalto v3 (rev1.0)" theme: they look amazing.
Recalbox on my desktop PC runs every emulator perfectly (even N64), much much better that on Raspberry Pi (the PC is an old core i5 (gen 3) with an ATI Radeon HD 4350.

The problem is: on PC, loading time is longer, and "uglier": GRUB menu appears (I know how to reduce the time it waits before booting, but I am not sure how to make it not appear at all). And, it does not load an image during boot (just black screen). While the Raspberry Pi version almost instantly shows an image, and boots faster.
Does anyone know how to edit GRUB in Recalbox and/or another config file to make GRUB disappear and show images during boot?

Regards,
Gabriel

[OyyoDams]

@mundodisco no help for this illegal image. Please download Recalbox from our website.