I hate starting these types of threads because it exposes my ignorance for all to see

I received some advice on blending r14 with Argon to achieve better temps.
The thing is r14 is very expensive so before I mix anything with r14 I want to understand how this will help.
So I started playing with a mix of Argon and Ethelyn (Note this cascade has 3 stages and the second HX is adjusted for -85c at the moment).

What im seeing is better temps with the Argon mixed in with a higher pressure to go along with it. The blend ratio is approx 15% Argon and the rest r1150.

Now argon should not be able to liquify at this temp and pressure so im assuming its just the added pressure which is helping my temps go lower. Can anyone help me understand whats happening? Because im at a loss