wvreeven I even have set up the iPad and the APP such that they both get a fixed ip address on the ethernet port (using an ethernet to lightning adapter for the iPad) so I can connect via a wire.
Be aware that the vast majority of Lightning to Ethernet adapters use the 10/100 Mbps Ethernet standard.
The newer iPads use USB-C connectors and the Gigabit standard. They are much faster than using Lightning adapters; so they are limited by the Raspberry Pi 4 mainly -- and you can get up to the 900 Mbps.
The M1 chip on the new 12.9" iPad will of course also render a downloaded Preview frame much faster. The spinning wheel seems to take about 1/2 of the time of the spinning wheel on an older pre-M1 12.9" iPad after the download progress bar has finished.
Moreover, you can use cheap USB-C to Ethernet adapters with the USB-C based iPads (all Pro models including the 11" iPad use USB-C connectors now). You just have to be careful to pick a Gigabit adapter.
The iPadOS Ethernet Settings should tell you the available bit rate for a given adapter.
That being said, I only use direct connect when I bring the OTA indoors to take flats.
My primary ASIAIR is connected directly to a dedicated eero 6 mesh router next to the ASIAIR (both are in a waterproof box at the base of my trip-pier that I leave outdoors 24/7), and I get up to 600 Mpbs through WiFi (the eeros have separate backhaul channels for transferring data between mesh nodes).
By the way, when you are taking flats and bias frames with short exposures, an Ethernet connector really won't be needed. If the frame rate is faster than the data transfer rate, ASIAIR will just skip rendering same of the frames on the tablet, but still save them to local storage. The same is true when you use video mode to capture planetary frames.
Chen