G28 w/ABL diagonal movement too fast

I've been struggling trying to find the bit of code inside Marlin that effects the speed of the X/Y movement from X0 Y0 to bed center when running G28. I have an ABL sensor installed and working fairly well, but the diagonal movement to the center of the bed is occurring way too fast and causes my Y-steppers to skip every time (maybe X too, but tough to tell). I have tried changing just about every part of the code that I could find that seemed like it might make a difference, but no dice! While it may not be the best illustration, I have a video of the issue here: [goo.gl]

This is more or less the copy of Marlin I am using: [bitbucket.org]

Does anybody have any definitive answers to how I might go about slowing that one movement down?

Thanks in advance!!