There are two parts to that question.
First, is it advisable? Yes, I think it is advisable.
What form it should take is another story, because the TIEAs can be set up according to one of two models, the UN model or the OECD model. The UN model puts much more emphasis on the needs of the developing countries, as opposed to that of the OECD, which is a boy's club, basically, of rich countries.
I don't know if we can backtrack over all the past FTAs and start imposing TIEAs on them, even on the UN model, but for new ones, anyway, I think it would be advisable. It would provide more security both to that country and to the Canadian tax authorities.