Is there a standard texture size to get world space scaling

I am trying to use BSP brushes to build very small spaced interior environments. Shelves, walk in wardrobes etc…

The problem I am getting is that the textures I have don’t have a correlation to how pixels to world scale.

Summery: I want to make a cube, give it dimensions and apply a material. Then to have the ability to change the dimensions x,y,z without the scale (like BSP brush settings) so that the material doesn’t get distorted.

e.g. I have a wood texture (made is a material) and apply it to a BSP cube. The texture is 1000x2000 (I know it’s not a power of 2 but it’s what I have to work with)
The BPS I can make(X is not in use) Y= 50, Z= 100. Any larger and it starts to tile. (It does not tile well on the Y axis as it was not made too.) This I thought was fine, thinking it was 20 pixels for 1 unit.
But; when I tested my hypothesis with 2 other textures that are 480x640, and 732x1400, Both were able to be applied to a BSP of (X is not in use) Y= 100, Z= 100. before tiling.

I wish to be able to know how a texture is applied to world space. As going to the pixel ratio this does not work out that double the pixel is double the size (I know more pixels mean more detail). If anyone can shine some knowledge that may shine some light to my curiosity. I wish to know this so that way I can set the unit size of the bush without affecting the scale and in turn affecting the scale of the image, as I don’t know of a way that a static mesh geometry can be manipulated as easily as easily as a BPS brush. A BSP works well so far, But sometime there will be brushes I need to make larger but It begins to tile. Some of these textures are not tillable. For when I do not have a tillable texture I wish to know how big to make the BSP by looking at the texture size(or know what correlates to the size in UE4), so I know what the max size I can make the BSP. If there is also away to know the size I think I can work something out with WorldAlignmentTexture node.