Can the UCG-Fiber power the Flex 2.5G PoE with PoE+?

At this point, I don't need the AC Adapter 210W, as I don't have any PoE cameras.

If I just connect PCs, laptops, streamers, filling up all 8 ports, and don't need any PoE output, is the UCG-Fiber's PoE+ sufficient to power the Flex 2.5G PoE? Will data transfer occur in this scenario or will I also have to use a DAC with the UCGF?

For a NAS that has an SFP+ port, should I connect that directly to the UCGF or to the Flex 2.5G's SFP+? In terms of features and capabilities, it seems like the Flex 2.5G PoE may be better because Ubiquiti published them while there is nothing on the UCGF.