Applying for Closed Work Permit with A70 Exemption code?

[RiversB]

Hi,
I currently have a job pending a work permit that requires an LMIA exemption code and I fit the criteria for the A70 Exemption code:

Under section R124
124 A foreign national is a member of the spouse or common-law partner in Canada class if they

• (a) are the spouse or common-law partner of a sponsor and cohabit with that sponsor in Canada;
• (b) have temporary resident status in Canada; and
• (c) are the subject of a sponsorship application.

Detailed Here

My googling leads me to people saying that it's only for the Open Work Permit in the spousal PR application.
Is there no way to apply it to my current jobs work permit? Where does the government say that it's only for an Open Work Permit?

Thanks