I think there is confusion between image size, print resolution and LO image window size… I have a similar workflow where I render in Enscape, export, post process in Photoshop or Lightroom then import final images into Layout for construction documents or presentations. I use paper sizes from 8.5x11 all the way to importing multiple renders on 24x36 sheets for both digital and print.
When you import into LO at least from what I understand thorough my experience, what you are seeing as the “size” is just the window size in LO that hosts the image. This doesn’t have anything to do with the image file size, image resolution or print resolution, it simply defines the space used on the LO sheet to display the image.
For print resolution, almost all professional printers are limited to 300dpi. No matter what your image size or resolution you cannot achieve greater than 300dpi print resolution. The resolution your image will print at depends on image resolution (pixel x pixel) size and size printed on paper. For an image that is 3072x2304 any size physically printed from 11"x14" and lower will be printed at 300dpi which is photo quality. Even printing this size of image up to 20"x30" which will be slightly lower dpi, will provide a fairly high resolution image.
For lower quality images you do have the potential to hit a print size that is not full 300dpi print resolution. A 2240x1680 size image printed at 300dpi begins to lose its detail and quality at print sizes over ~8x10".
I’ve found a lot of information related to digital image sizes and printing that directly relates to processing and printing our rendered images on general photography sites.
Hope this helps…