Change font to highlight words with expressions - Mogrt

We have a client that we work with a lot.

In their brand guidelines they work with big chunks of text, left justified, in a light version of their font but highlighting important words with a semibold version of the font.

Text is often sliding in line by line from the left.

I REALLY like to make it a Mogrt since i do the exact same animation over and over again.

But it seems like there is no way of working with different font weights in the same block of text if you want it dynamic and make a Mogrt or use it with Master Properties.

I saw this clip that used the Text Animator to highlight words with the index of the word.

How to Highlight words easily - After Effects Tutorial 

The idea of working with slider is good but it only changed the color of each word.

I'm open to any suggestions, hacks, over complicated, slow.

I want to target specific word/words not whole lines and to be able to have more than one highlight section.