Hi Rehabman,
I had the same lag problem on my HD5500 using ig-platform-id 0x16260006.
I tried following your guide by removing one connector from the pipe count and putting port 204 (this is the port my Laptop is using for HDMI) into the place of port 105. After rebooting, the HDMI connection didn't work anymore but the lag was gone (I followed the steps from your post but just applying it for the Broadwell framebuffer/data). Then I figured out that when I don't remove the unused port from the pipe count and replacing
<01050B00 00040000 07050000 02040B00 00040000 07050000>
with
<FF000000 01000000 40000000 02040B00 00080000 07050000>
the HDMI connection works and there is no lag when logging and waking up after sleep.
The above patch is the only one needed. It also enables HDMI audio on port 204.