I managed to bring both screens up at 30Hz on boot by passing video resolutions as kernel parameters

video=DP-3:3840x2160@30 video=DP-4:3840x2160@30

This caused me to realize I was actually loosing the kernel boot output after the framebuffer kicked in (I was loosing a five seconds or so of green service [OK]s) output prior to wayland starting.).  

Now, with the displays active @30Hz prior to wayland, wayland has no problems starting on both screens, and my 60Hz settings are restored when wayland starts, as it remembers the display configuration.  *HAPPY*

In summary, it is working the way I expected it too, by simply forcing 30Hz during early DRM/i915 framebuffer loading and then letting wayland restore my settings for the 60Hz configuration.  

I even updated my edid with the proper 32" DisplaySize, fixing the bug in the displays, so it looks proper and does any scaling math accurately.  

I no longer think this bug is a wayland issue, but not really sure where to move it.  

My complete set of kernel parameters is shown below, which covers some corner cases where replugging things enumerates the ports as DP-5 and DP-6 rather than default DP-3 and DP-4, and includes my update to edid which updates DisplaySize to "710 400"

None of the errors are important,  I will briefly explain.

The early edid errors are simply because my edid overrides are not in initramfs image, but they are still loaded later prior to wayland from /lib/firmware/edid/.

The DPCD read error is emitted due to an unused port on the dock.  Port 1 and 2 are the ones used for DP-3 and DP-4 in my case. I determined this by observing that if either monitor is absent on boot, another one of these lines (with Port 1 or Port 2 specified) appears. 

$sudo dmesg | grep -i drm
[    0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-5.13.0-39-generic root=UUID=55cd97c8-08cc-4c11-8fb2-a7e0e7b10386 ro drm.edid_firmware=DP-3:edid/lg32edid.bin,DP-4:edid/lg32edid.bin,DP-5:edid/lg32edid.bin,DP-6:edid/lg32edid.bin video=DP-3:3840x2160@30 video=DP-4:3840x2160@30 video=DP-5:3840x2160@30 video=DP-6:3840x2160@30
[    0.054811] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.13.0-39-generic root=UUID=55cd97c8-08cc-4c11-8fb2-a7e0e7b10386 ro drm.edid_firmware=DP-3:edid/lg32edid.bin,DP-4:edid/lg32edid.bin,DP-5:edid/lg32edid.bin,DP-6:edid/lg32edid.bin video=DP-3:3840x2160@30 video=DP-4:3840x2160@30 video=DP-5:3840x2160@30 video=DP-6:3840x2160@30
[    1.785350] fb0: switching to inteldrmfb from EFI VGA
[    1.841274] i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/kbl_dmc_ver1_04.bin (v1.4)
[    1.930861] i915 0000:00:02.0: [drm] GuC firmware i915/kbl_guc_49.0.1.bin version 49.0 submission:disabled
[    1.930877] i915 0000:00:02.0: [drm] HuC firmware i915/kbl_huc_4.0.0.bin version 4.0 authenticated:yes
[    1.936210] [drm] Initialized i915 1.6.0 20201103 for 0000:00:02.0 on minor 0
[    2.344327] i915 0000:00:02.0: [drm] Cannot find any crtc or sizes
[    2.390395] i915 0000:00:02.0: [drm] Cannot find any crtc or sizes
[    2.420949] i915 0000:00:02.0: [drm] Cannot find any crtc or sizes
[    2.455474] [drm:edid_load [drm]] *ERROR* Requesting EDID firmware "edid/lg32edid.bin" failed (err=-2)
[    2.547006] [drm:edid_load [drm]] *ERROR* Requesting EDID firmware "edid/lg32edid.bin" failed (err=-2)
[    2.639779] fbcon: i915drmfb (fb0) is primary device
[    2.665195] [drm:edid_load [drm]] *ERROR* Requesting EDID firmware "edid/lg32edid.bin" failed (err=-2)
[    2.765720] [drm:edid_load [drm]] *ERROR* Requesting EDID firmware "edid/lg32edid.bin" failed (err=-2)
[    3.083890] [drm:edid_load [drm]] *ERROR* Requesting EDID firmware "edid/lg32edid.bin" failed (err=-2)
[    3.179332] [drm:edid_load [drm]] *ERROR* Requesting EDID firmware "edid/lg32edid.bin" failed (err=-2)
[    3.436412] i915 0000:00:02.0: [drm] fb0: i915drmfb frame buffer device
[    5.925513] systemd[1]: Starting Load Kernel Module drm...
[   15.296276] [drm] Got external EDID base block and 1 extension from "edid/lg32edid.bin" for connector "DP-3"
[   15.310181] [drm] Got external EDID base block and 1 extension from "edid/lg32edid.bin" for connector "DP-4"
[   22.079914] [drm] Got external EDID base block and 1 extension from "edid/lg32edid.bin" for connector "DP-3"
[   22.094138] [drm] Got external EDID base block and 1 extension from "edid/lg32edid.bin" for connector "DP-4"
[   29.173660] [drm:drm_dp_mst_dpcd_read [drm_kms_helper]] *ERROR* mstb 00000000e44412a7 port 3: DPCD read on addr 0x4b0 for 1 bytes NAKed