How to change default scalability settings

I have an issue with my terrain . It deforms when playing in packaged game or standalone .
After alot of frustration I found it is the Streaming Pool size that affects it .
The maximum amount of 1000mb , is just not enough , and the terrain heightmap is mip-ing , and deforming my terrain .
Now when I use the command r.Streaming.PoolSize 3000 , everything is fixed .
The question now is how do I do that without always entering the command .
I tried making blueprint to execute the command on begin play - doesnt work , everything is worse .
I tried searching around here for some other way fo starting the game with the command - nothing .
I tried changing the Scalability.ini files , changing the PoolSize to 3000 in every place even the low levels . It doesnt whant to take the change . After I enter the game , the file reverts to its default . I tried setting it to read only - again nothing .
So my question is where and how do I set my own custom values for the engine scalability settings . The scalability.ini doesn’t work .

I would set the “Never Stream” setting in the texture asset that defines the heightmap.

That did cross my mind , but it appears the heightmap is not stored the usual way. You can’t find it in the content browser.
Since then I use a blueprint to increase the poolsize in the very begining of the game. That’s not ideal though.