As an a side
My Mrs (PR) has just had a visa transfer approved for an expat staff that she employed. She has split her partnership (not formal legal partnership, but contractual arrangement) from an established limited co. and used her sole-pro entity to re-employee the one staff she has.
The sol pro was not the main trading entity for her business (the vast majority of the modest revenue went through the partnership business that employed her 1 staff) and thus the sole pro, whilst 4 yrs old, has a very very small trading footprint - doesn't even have a business bank account.
So great that we've been able to get immigration to play ball. (I spent a lot of time carefully building the case to present to them).