Related Product Issues With Changing Default Variation

We are finding if we have an item in 2 sizes and we set related products for the default one it shows for both. But if the default one goes out of stock as per the setting the default changes - but then related items need re adding for the other variant anew.

Annoying - any way around this or has it been fixed in later versions? (am a year out of date)

Try to reproduce it on the demo. If the issue still exists, just make a post in the bug tracker