Does it matter if I could reasonably be considered an employee of my main client for PSB status?

Yes, this hypothetical question is central to the whole analysis, not just one factor among many. The Income Tax Act's definition of a personal services business is built directly around asking whether, absent the corporation, the individual providing the services would reasonably be considered an employee of the person or organization receiving them, so this isn't a loose, general consideration but the actual legal test the classification turns on.

To answer that hypothetical, CRA and the courts fall back on the same substance-over-form factors used in ordinary employee-versus-contractor cases, control over the work, ownership of tools and equipment, whether there's a genuine chance of profit or risk of loss, and how integrated the person is into the client's business, applied as if the corporation weren't in the picture at all. If those factors point toward an employment relationship once you strip away the corporate structure, the PSB classification generally follows.

Because this hypothetical framing is baked into the statutory test itself, someone assessing their own risk should genuinely ask themselves this question honestly, based on how the work actually happens, rather than treating it as a formality that incorporation alone resolves.