I am paranoid :o) so I would use the correct terms in the first place, this is one of those things that will make you a better print production guy.
most print PDF defaults compress any images over 300dpi down to 300dpi
No, they are not compressed, they are resampled, and this is a checkbox that can be easily deactivated.
DPI
The unit you should use is PPI, regardless that they are commonly used as the same unit they are not.
I make sure images will be at least 150dpi
150 PPI as a final resolution is probably too much. 100 PPI is a good resolution that will not be visible on an image at 1 m.
The images you export at 10% at 300PPI have a final resolution of 30 PPI, which is in fact still a decent resolution. It is a small square of less than 1 mm when viewed at a couple of meters is again unnoticeable. As long as the text remain as a vector, this is still a good file.
Regarding your question
For anyone working in print production, would you just run it as is because it's not usually a problem
I am not in that part of the chain of print production, but in any case, that specific issue is no obstacle to print it as it is. I mentioned it early 30PPI is a good resolution for a few meters print. There is no way to know you intended a greater resolution but did not unchecked the resample box.
An example of a warning that should not be allowed to continue without double-checking is, for example, a small black text in RGB colors. That kind of warning should be stoped and called upon.
are there no preflight systems that pick this up?
Probably you can setup a warning if a file has less PPI on a file than some amount, but 300PPI is a standard good resolution so, there is nothing to warn about.