Sorry, yes, I thought you were talking about the 20 credits that came at 70K
The answer is that 20 eUps, especially at the P25K level, probably aren't worth a ton. The number of eUps required depends on the destination and fare class. AC seems to have nuked the detailed chart that showed how distance impacted eUp requirements. The much less useful eUpchart that only shows "starting at" certain numbers of eUps is here:
https://www.aircanada.com/ca/en/aco/...calculate.html
If you're used to buying Standard or low Flex fares, those 20 eUps will disappear quickly. If I recall correctly, if the route is >1,500 miles in North America, it will cost you 15 eUps to upgrade low Flex fares, for instance. So one YYZ-YVR flight would consume 75% of your credits. Internationally, 20 credits won't get you much unless you're buying a pretty high fare. If you go to Europe, it's 21 credits to upgrade a one-way in Flex, plus a $500 co-pay, to upgrade to business class.
Even if you find a fare you like, and that you have credits for, you're also subject to the booking window. Other than Latitude or PE Flexible fares, upgrades can only be requested a certain number of days in advance, and that window opens earlier the higher your status. With P25K, you're almost at the bottom of the heap.
If you're waitlisted for an upgrade (your window has opened and you've requested an upgrade but it wasn't available at that time), you're also behind all of the people with higher status (who are in the same cabin) for any upgrades that do become available. So if one seat becomes available, but there's an SE or 50K on the list ahead of you, no upgrade.
Historically, some routes have been much more difficult to upgrade than others. Typically routes with more business traffic and status passengers are more difficult to upgrade, as are those where most J seats are sold. When the J cabin on YVR/YYC-YYZ is half paid and half SEs, you're going to have trouble getting an upgrade as a 25K. Same with, say, YVR-SYD, where upgrades and points redemptions are scarce. But you might have better luck with, say, YYZ-FLL or YVR-BNE.
I don't want to get you too down on the eUps, because you may be able to use them for something cool, but just beware that it's not going to be easy