I often push up against the size limit for the direct solvers. I already find that the limit in Solidworks 2020 is higher than in 2018, but I don't know what it is without iterating mesh size.
Is the problem size limit documented anywhere?
Also, RAM is relatively cheap today. Can't the limit be pushed up in the compiled code dramatically, or made a run-time flag set by the user (with understood trade-offs)? I remember at my first job often going back to the lead developer to ask for custom compiled builds, pre-allocating more fixed space to one matrix over another - but that code was in FORTRAN 77 and our workstations had a 'generous' 32 MB of RAM.