Would it really help? The patterns would be the same anyway.
The real “problem” here is that KiCad doesn’t use “clear polarity” circles for via clearings in the zones. Each hole is traced with a bunch of small consecutive lines and there are many of them.
In version 5.99 you can choose the new zone filling method which doesn’t have those extra segments which effectively double the amount of the needed information; in your case it would practically reduce the layer file size by almost 50%.
