Yes, with the broken version(s) of C:B, wxsmith never renders the attached project correctly, and yes, there *would* be a scrollbar in the UI view if it rendered completely. So maybe the scrollbar problem is at the heart of this whole mess?
As I noted in my previous post, I was able to get a working version of C:B trunk by compiling against wxWidgets-2.8.12.
Out of curiosity, I went back to the virtual machine set up on my 4th-gen Core i5 computer and compiled wxWidgets 3.03 using --without-subdirs --enable-xrc --enable-unicode --enable-monolithic. I then compiled the C:B trunk against this version of wxWidgets, and it compiled with no problems. The result *mostly* works - it will render the project correctly, but when attempting to scroll down to see the rest of it, the rendering flickers, briefly showing the rest of the frame, but then blanking out. However, if I scroll down part way and hit F2 to make the logs disappear, it will show almost correctly - the exception being that a spacer is showing up only as a line.
So, with additional curiosity, I came back to the laptop with the 7th-gen Core i5, uninstalled my now-working copy of C:B+wxWidgets 2.8, and did the same as above - created a wxWidgets 3.03 monolithic library, and compiled a fresh version of the trunk against it. Again, it compiled fine, and again, it *mostly* works - same flickering when trying to scroll down to see the rest of the frame. This time, however, hitting F2 does not result in the frame showing correctly - the bottom part still briefly flickers and then blanks out. So again a slight difference in how it runs on this processor (or as you say, likely GPU) vs. the other.
But mostly is not good enough, so, I've gone back to the C:B + wxWidgets 2.8 version. Again, I don't know what, if anything, I will lose by running C:B off of 2.8 instead of 3.0, but AT LEAST IT WORKS!!!
And again, oBFfusCATed, thank you so very much for all the time you have taken on this. Even though my solution has turned out to be to regress to wxWidgets 2.8, I hope the experience provides some insights into ongoing or future problems that may show up as C:B continues to transition to wxWidgets 3.x!