Just received DisplayPort cable and conducted test with the LG 29UM55-P:
When using the HDMI or DisplayPort interface with straight HDMI-HDMI/DP-DP cables, the mouse freezing was still encountered. While it appears that the HDMI/DP ports farthest from the power cable both encounter the repeated freezing issue, the HDMI/DP ports closest to the power cable encounter the mouse freeze once per reconnection of the display and then resolves.
I will repeat the Closer-Farther port test with my HP2159m and HDMI cable to see if my other dock has the same port behavior distinction.