XCOM 2 Modding Alert Level

[flamewavelight]

Hi. I am looking to mod XCOM 2 WOTC to experience the mid-game from the time I start. I played through the early game many (many) times, and have a decent understanding of Troopers/Officers/Sectoids/
Need to get a better understanding MEC/Purists/Priests/Stun Lancers.

I am not that comfortable with mid-game, and would like to "start" a mid-game.

There is a mod that changes starting Force Level, but it causes a crash, so I made the following changes (sucessfully):
Starting Force Level: 5
Starting Squad Size: 6

(this was a little too much for me, and I am going to bring starting force level to 2 or 3. OR I will reduce the number of kills needed to promote so that I start with Corporals, and then I can keep Force Level 5).

In parallel, I am looking to increase the challenge, so I believe there is also a parameter called AlertLevel.
Which file is it in?

And how will changing AlertLevel change my experience.

Help appreciated.