Hello Luki
You can plug the supply line into any input without any problem.
This way you lose a port, but it works wonderfully.
Another possibility, as you have already noticed, is to use one of the SFP ports. For this you need a plug-in module, e.g. Ubiquiti UF-RJ45-1G: SFP to RJ-45 module. Then you can certainly use this input as well. I had enough free ports, so I haven't tried it yet.

Hi Luki, if you connect your US-8-150W switch to the Strohm, the 8 ports there automatically detect whether a PoE(+)-capable device has been connected to one of these ports. This only means for you: Switch on, update to the latest firmware and connect the Ethernet cable of the PoE-capable device to one of the 8 ports. If the device does not start on the Ethernet cable (does not receive power), then there are various possible reasons, such as no PoE-capable Ethernet cable or the device requires a PoE standard that is not supported by the switch.

The switch has its own power cable and connection. For the devices that you connect there via Ethernet cable, you must enable PoE power with the software,