Hello,
I just leave a quick reply here to share my feedback.
I received today my cheap chinese 7001 angular bearing (
https://fr.aliexpress.com/item/32847...425a6c37Hb0PSN) and they didn't change anything
I still have the exact same amount of backlash in the screw than with the originals bearings. I have ordered 0.1 mm washer shim and I will try to put one between the two bearings to see if it helps !
If it's not, I will just follow the advices here and just go with them to later machine my own BK12 support with proper bearings.