Mac mini 2020, Akitio Node Titan eGPU enclosure, LG Ultrafine 5K 27" with TB3 - can't this work?

The eGPU enclosure has one Thunderbolt 3 port. It contains a Radeon RX 580 which has HDMI and DP ports, however these can't be use with the LG. I have connected the Akitio to the Mac mini TB3 port. Since the LG only has TB3 ports, I have connected it to the Mac mini. I've read it's better to connect a monitor to the eGPU, but that can 't be done with this setup. The readings suggest that with my setup, the Mac sends signals to the eGPU which then returns the processed signals to the Mac. The Mac then forwards the signal to the LG. This setup is not as efficient as one where the eGPU forwards signals directly to the display, but that's what I'm limited to.

The Mac mini does "see" the eGPU as the GPU History (via Activity Monitor) includes graphs of the built-in Intel graphics card and the Radeon in the eGPU, but nothing ever displays in the Radeon chart. Only the Intel chart shows the bar graphs. When I invoke "Get Info" on some apps, like Lightroom or Photoshop, the info does not include the "Prefer External GPU" option (no apps do).

Can I not have the eGPU used instead of the integrated Intel graphics card in the Mac?