The "familiarization" process applied to STCs is just a procedure that was developed under the US/Canada bilateral agreement. The FAA uses the same process which is now commonly referred to as "airworthiness review".
This review is neccessary to determine if the foreign STC meets the intent and certification basis of the corresponding TCCA Type Certificate of the associated aircraft. If it doesn't then it gets rejected and bounced back to the responsible FAA ACO for review and/or revision. Again, a reciprocal procedure is used by the FAA if a Canadian STC is being considered on an American airplane so its not a one-way street.
TSOs like ACs are not all automatically accepted. The are just one means (not the only means) of approving equipment. TCCA has the PDA and TC processes in place for appliance approval in Canada. TSOs and JTSOs are just another example of foreign approvals that must be reviewed and formally accepted by TCCA.
A new CAR/AWM chapter will soon be available (chapter 521) that will consolidate 511 and 513. It will more or less mirror FAR 21 in an effort to harmonize our approval methods (including TSOs and JTSOs) with the FAA and the JAA.
One other tid-bit, TCCA actively participates with the FAA and JAA in the devlopment of policy material such as ACs in an effort to harmonize and more easily form acceptance of the respective policy. Therefore, the idea that TCCA uses FAA or JAA guidance for free without contributing development ideas and manpower is just plain wrong. (Not pointing fingers here, I've just heard this opinion alot)
As a matter of fact, the FAA has demonstrated a desire to use the TCCA model for personnel licencing, delegation, and aircraft modification to address many of the problems they are experiencing.