Acquiring Spanish Citizenship (Canadian citizen)

Hi everyone. My name is Amine, I'm 28 year old and I've been living in various countries in Europe since 2016. My partner is Spanish and I obtained my Spanish residency through civil union. After 5 years spent on the continent I really don't see myself living anywhere outside Europe and I am therefore in the process of acquiring Spanish citizenship, ultimately to be able to live and work where I please in the EU. I am well aware that Canada and Spain do not have a dual citizenship treaty but I've seen several people (mostly from the USA) aquiring Spanish citizenship and retaining their original citizenship because Spain doesn't verify that applicants have indeed relinquished their original nationality.

My question has to do mostly with the logistics of have a citizenship combination that is technically prohibited in Spain. As is the case with American citizens, Canadians don't lose their citizenship unless they apply for citizenship renunciation directly at Immigration and Citizenship Canada. A Canadian citizen swearing they're renouncing their citizenship is a Spanish 'Registro civil' is not enough for Canada to stop considering the applicant as a Canadian citizen.

This leave people like me in a kind of legal limbo with one main question:

When / if I visit relative and friends in Canada, would it be possible for me to use my Canadian passport? I'm aware that Spanish border agents will notice that exit and entry stamps don't add up in my Spanish passport and will most likely ask to see my second passport. Would I be in trouble if I enter Spain with both passports?

What if I enter the Schengen through another country e.g. Portugal or France? Will there be any way for Spain to see that I've been using my Canadian passport?

If you have any experience with this I'd love to hear your opinion on this

Thanks a lot

Amine