Small business owners are often a hybrid of capitalist and market-socialist in the sense that they are often workers for their business (making the business worker-owned to some degree).

For example, if I own a small cafe with 4 staff members and I work 40 hours a week in customer service alongside my staff and then another 20 hours handling the logistics and other management related stuff while my staff work 30 hours each then my small company would be a hybrid of capitalist and market socialist since the worker-owner is doing 33% of the labor to run the company.

So I like the idea of allowing small privately owned companies even under DemSoc or Communism, and then once the company grows to 50 or more employees it should either become a worker co-op, unionized or nationalized.