How to enter FEL-Mode over MicroUSB in NanoPi NEO Core

[cggfgd6s]

Hi all,
I've read a lot of postings in this and other forums so far - but didn't found a solution.
According the schematic of the NEO Core it seems that the Pin to enable the FEL-Mode in H3 is fixed pull-up to Vcc. But what does it mean, is it always enabled or disabled?

I want to flash the eMMC via USB-Cable, without the need of inserting an SD-Card (due to installation of multiple NanoPis).

So: How to bring the NanoPi NEO Core into FEL-Mode to flash the eMMC?

Thanks
Achim

[cggfgd6s]

Nobody ever used FEL-Mode on NEO Core????