This may have been addressed somewhere in the last 10 or so pages of replies, but in case it hasn't, and for your sake, I strongly encourage you to seek some form of professional advice. I believe the high likelihood of being "criminally inadmissible" to Canada would hold you back from regional employment in the current hiring environment, much less ACMI, other major, or legacy.

I believe this is a far bigger roadblock than you understand based upon your statements in the first 8 or so pages I read. If this has otherwise been addressed, please disregard. Just trying to help a potential downgrade and/or furlough facing brother or sister out. (Full disclosure: That's not me currently, but I've been there and done that, and getting that t-shirt suuuuuucks).

Your DUI makes you presumptively inadmissible to Canada for at least 10 years. Luckily, it sounds like you received it before December 2018. Apparently, it's been upgraded to a felony equivalent conviction in Canada as of then, but offenses prior to that date are treated as lesser (equivalent to what they were then in Canada) for immigration purposes. You have two reasonable options to regain entry. Criminal rehabilitation 5 years post conviction and sentencing (including probation), and deemed rehabilitation after 10 years. But you will have to apply for either. Criminal rehabilitation requires submitting a packet to an immigration office, and you'd probably want the help of a lawyer. Deemed is relatively painless; you can do it at any port of entry, but it has to be applied for in person. I went with a friend who needed to do so for a conviction nearly 20 years ago, and it took all of 20 minutes. Before this, he'd missed out on a couple of regional airline job offers, including one where he'd previously worked in another department at the airline.

As far as I understand it, "deemed rehabilitation" is no longer an option for offenses committed after December 18, 2018, but honestly, I think you ought to go the "criminal rehabilitation" route, given that you don't believe you necessarily have 3 more years of secure employment.

I was convicted of driving while impaired by alcohol or drugs. Can I enter Canada?

Overcome criminal convictions - Canada.ca

Canada DUI Entry: Can I visit Canada with a DUI? | Canadavisa.com