What affect does 'Maximum texture size' have on Texture Streaming performance

My first post!!.. (I think)

Background:

I have been creating an ArchVis scene for some time now and have been generating all of my material textures at 2048x2048px. Up until recently this has not caused any problems, however having previously concentrated on building components I have now started populating the scene with numerous smaller assets - e.g. light fittings, CVTV, seating, Monitors, etc. I have continued to use 2048x2048px resolution textures for all assets no matter what scale.

Consequently I have now run into the ‘Texture Streaming Pool Over’ message - by varying amounts (up to 1GB at times).

My target lightmap texel density is 1 - as I am using area shadows and am looking to avoid pixelation for cinematic close-ups. The majority of my lightmaps are set to 256x256px with many below. There are some at 512x512px and a handful at 1024x1024px - the ones I couldn’t segment any further i.e. floors.

To the point (my question(s)):

Will going through each texture asset and under ‘Compression’ setting the ‘Maximum Texture Size’ to smaller sizes (for textures that don’t need to be 2048x2048px) make any difference to the texture streaming performance?

I have done this for a number of assets (and on others have checked ‘never stream’) with no avail. Within the texture editor the ‘displayed’ and ‘max in-game’ texture size is reduced as is the ‘resource size’, however I am unsure whether the texture streaming system ignores this process and caches the origin texture size regardless. Is this workflow worth proceeding with or am I better off just reducing the size of the textures outside of UE and re-importing them? I’d like to avoid doing this if I can - but needs must.

I’m fairly sure (although not certain) that the lightmap density is not the problem as this issue has only arisen since I started adding textures to materials.

Any help or guidance would be very much appreciated.

Thanks!