Regarding what Andy and Tim are reporting and discussing, does make any difference in file size dependent on what the Save as .tcw Setup options shown below are set to?
HI Alvin. Good thinking. Yes it makes a difference in 2019 / 2020.. I created a simple drawing, Just a box with two holes in it. I just tried various settings in 2018, all I could get was a file size change from 212 KB (plan view) to 266 KB (active view). As this is just a preview image, I would not expect a huge file.
In 2020 its temperamental (for me). When I first opened the file, it was set to active view. and file save was 3.8 MB. Plan view was the same. So I set it to none, and the file was 221 KB. Anyway. after switching things on / off a few times, And Closed and reopened the file, now plan view is 3.8 Mb, and active 270 KB. and in all subsequent drawings, plan view is huge and active view small. (Note all the saves were in draft render).
Why 2019/2020, is so different from 2018 I have really not go a clue. Prior to 2019 it looks like plan view did a zoom extents and saved just the drawing - no white space. And saved as a sort of thumbnail file. In 2019 / 2020 plan view appears to be ignored, it just takes a screenshot of whole view including the white space and the world coordinate x, y z. icon (if displayed), And saves as a full size bmp image.