I would disagree. There are far more reports of people being denied at BKK and DMK, and to some extent, HKT (Phuket), compared to almost no reports of denials through the smaller international airports.
is that really the case? Wouldn't one visa simply cancel the other one out? So for example, someone with an elite visa that is expiring later this year could not apply for a DTV visa until the elite visa has expired, to replace the elite visa?
It's not really an issue for Canadian citizens. A drivers licence or utility bill is typically enough. They are more concerned when someone has a passport nationality that differs from their location.
If it is a multi entry tourist visa, you get 60 days upon entry, not 90. You have to go to an immigration office after entry to extend to get the extra 30 days.
Imagine getting a 5 year visa by proving you frequently attend music festivals. What do you need to prove, that you have ferry tickets to go to Koh Phangan for a bunch of Full Moon Parties? 😁