Certain British coins produced during the reign of Victoria carry a Die Number. This clever feature identifies from which reverse die a coin was made. As expected, there are some collectors who pay attention to these clearly stamped numbers and would like to obtain an example struck from all the various dies used to produce a certain type and date of coin. It's a wild guess, but I'm willing to bet some die numbers are harder to find than others.
Instead of using contrivances like privy marks, what if the RCM began numbering the dies used to produce their various NCLT products and bullion related coins? I think this innovation would be a big hit with collectors. The “first strikes” would come from Die#1 and never be confused with subsequent production. What might be fun for collectors is to discover that Die# 4 or perhaps Number 7 actually produced the fewest coins of that date. The RCM could even sell special sets that include one coin of each type struck from all the dies used in that year's production run. In the case of commemorative coins struck in Proof I can't imagine that many different dies would be used for the entire production run.
If die numbers could be added in 1840's it certainly would be an easy task to do the same thing today. If the RCM really wanted to get fancy they could number both the obverse and reverse dies and potentially create all sorts of collectable combinations.
Why dies were once numbered really doesn't matter. I think it's obvious that such a feature would be a welcome and fun addition for some collectors. My personal choice would be to have a pair of coins to illustrate the first and the last die used to produce a certain coinage. Those who didn't care about the die numbers could simply ignore them.
Those who find fault with the idea of numbering dies could suggest that such a scheme would allow the Royal Canadian Mint to purposely limit the use of certain dies to create artificial rarities. My response would be that all of the products created by the mint for the collector market are done seemingly to create demand among collectors so adding a new twist like die numbers would do nothing to add doubt to the institutions credibility. At least in my view adding numbers to dies seems fairly tame when compared to creating $8 denomination coins so as to appeal to certain members of society.
If you like the idea of having coins struck from numbered dies why not send the RCM an email and reference this article. Who knows, they certainly have done stranger things.