No. I suggest trying to refrain giving advice when you have no clue (or only assumed clues) of the actual circuit setup in a country with different electrical codes than yours.
There's only ONE RCD in the picture. The things labelled B40, B32 B20 etc are NOT RCDs. There's a reason why this profession is regulated.
So what does your electrical code specify for the maximum continuous load on a 40 amp circuit?
It's not about what the Canadian code specifies and when. How do you know it is a 40 amp circuit? He has a 100A main breaker and if you add every number you see in the picture you get way more than that (162, right?). Did you ask what other loads he has in the house? The RCD is good up to 80A for his whole house (except the garage), which leaves only 20A for the garage. I hope she still wants to live there .. the rest of the house still needs enough juice for the oven, boiler .. etc. He'll trip his pants out, or do some "arc-welding" in that panel if everything start at once, as after a temporary blackout or mains disconnect.
Maxing out a 40amp circuit (as per your understanding, with 32A continuous) when that circuit is not there might burn his garage out. The issue here is that you started giving advice based on what you think he has on in there .. and if he follows your advice he might burn his house down. I wonder how you can sleep at night ..