Scatterplot as a matrix

[jozef_sykora4-1]

First of all, big thanks to @lindsey1  as this is a follow on from her topic Measure vs. Measure Scatterplots (3.28+) | Looker Community.

As many users before me, I am currently trying to find a workaround to create a a decent scatterplot. I have gotten as far as having measure vs measure scatterplot. See below(dimension1 is hidden, measure1 is on Y axis and measure2 is on x axis):

measure vs measure scatterplot

This is good but I have two challenges now:

1. I need the dimension1 name included in the scatterplot. 
2. I need to divide the scatterplot to 4 quadrants

Ref number 1. I now understand that there might be a way to include the dimension1 name in scatterplot by using liquid variable in a html element of a measure. Can anyone help me with that?

Ref number 2. I have gotten as far as creating a horizontal reference line (Visualization - Edit - Y - Markings - Add reference line) but is there a way to add vertical reference line as well? I found a bunch of examples but they only work with one measure. How can I create a vertical reference line for a measure vs. measure scatterplot? 

Thanks!