Here with my projects I use the following method to create the assemblies and then the IDW.
In the assembly i create 2 LODs with SUBISTITUTE, one with normal datails and one with almost nothing, just as a reference to others models and for a layout e.g..
In the top assemblies i user the first LOD SUB with normal details because it turns the IAM easy to work (if i use the MASTER LOD it becomes impossible to work with 100k ~ 200k parts in the IAM). So, when im working in the IAM everything is perfect, with JUST SOME parts loaded in the memory.
So when i need to go to IDW, I put the base view with my LOD SUB and i can work fine, untill I try to use baloon or even the BOM.... when I activate the BOM, ALL the assembly is loaded and then becomes impossible to work, like if in the LOD is loaded 20k parts....when I load BOM all the 200k parts are loaded, even with BOM PARTS ONLY DISABLED and with the right LOD selected to use in the BOM.
So, is there a way to solve this ? Or isnt that a problem?
Because I think it makes no sense; If you create those Subistitutes its because you dont wanna load everything, but right in the end, everything goes to the memory.