This ended up being a costly learning experience (read, failure). Having had some experience with surface mount assembly, I let the description's statement of relative (to the main board) ease convince me that I could do this. There were challenges, but I managed to get everything except the microSD card holder and the flex ribbon connector. Those ended up destroyed, so I had to order replacements, adding another delay while waiting for parts. Finally, I was satisfied that everyone was soldered and solder bridges fixed, so I want to assemble. When I tried to insert the flex strip, the connector came off, ripping out the traces. End result, an expensive learning experience and an e-ink display that needs a controller board.

In other words, while it might be easier, it isn't easy. Do not attempt unless you know what you're doing.

And a minor complaint about the assembly instructions: It should be clear that the through-hole tactile buttons get mounted on the reverse side from the SMT components.