@droftarts thank you for the reply and sorry for the late reply.
After sending the message I continued tinkering and searching for clues of why that happened, and I've discovered what was the problem:
By using the BLV mgn profile on Cura, the special option "Set Relative Extrusion" is disabled, meaning that when I was applying the "set relative extrusion" command inside the gcode, the acual extrusion values inside the print gcode were still absolute and exponentially told the machine to extrude more and more filament, more than it could do.
By removing the relative extrusion command, the printer worked like a charm.
After that, I've tried using other slicers like Orca, and it managed to convert to relative extrusion with no problem, with also a lot more of options for me to customize. So I'll probably stick to it from now on.
That was genuinely my bad to not have thought of that before, tomorrow I'll set this post to resolved for the posterity.