SU file linked to another SU file with very slow "Reload" issues

I have an SU file (file B) that contains an imported SU file (file A) with the whole house model. The only purpose of having SU file B is to add the section planes for plans and sections.

My issue is the time to “Reload” file B after changing file A. It takes much longer to “Reload” than to open file B. File B has also crashed a couple of times. File A has never crashed.

Any tips or help reference anyone can point to that might help speed things up? Is this not a good workflow?