In the US, there are recipes with either evaporated milk or heavy cream, and they so taste subtly different. Evaporated milk, as you likely know, has a bit more of a 'cooked' almost subtle umami hint to it. Some desire that for caramels. I would say, having made both types, that you taste the dairy a bit more than you do with heavy cream.
Counter to a previous comment, I have never seen a caramel recipe with sweetened condensed milk used; though it would be possible, I would not substitute it in the recipes you referred to or I have made, as it would be overly sugary, weaken the brown or browned sugar taste, and lacking in the dairy/milk/cream taste, which is a big factor in loving caramels flavor.
With the heavy cream caramels, I think more of the sugar and butter taste comes out. It is hard to explain unless you taste them side by side and then how long the cooking and if the 'milk byproduct' doesn't curdle (not happened to me, but I have had some with this effect), the evaporated milk and even corn syrup can help counter this.
Corn syrup is often used to encourage the sugar crystals to dissolve so the outcome isn't gritty, as in fudge where it wasn't cooked properly. One crystal and the whole batch of fudge can turn granular, including caramel fudge or what is often called blonde or white fudge or penuche.
A lot of recipes are done with 'what is in the larder', and so evaporated milk was likely substituted during times of limitation such as the Depression, Dirty Thirties, wars, etc., and even if the household budget required. I even keep a can or two on the shelf in case I run out of cream. And evaporated milk in a creamed soup taste very different than when heavy cream is added. Again, you can taste the cooking in the evaporation process. The same with substituting evaporated milk for regular milk when baking bread. That 'cooked milk' taste comes forward.
I would say that caramels are delicious in and of themselves as it is the melding of brown or browned sugar, butter, and cream (or evaporated milk) so I wouldn't worry about it. Since cream often shouldn't be cooked at higher temps or for very long, or it will separate or curdle (but not as much in cooking as most tout), I would say that evaporated milk is a safer choice for success as in less chance of curdling. If I was to choose, I guess I would prefer the one with heavy cream. Additionally, about cooked milks, some I have known like to add sweetened condensed milk to their coffee instead of half 'n half or cream with sugar. I don't care for the cooked taste of the sweetened condensed milk in that either as it is quite pronounced, but I do use that product for many other things and with great aplomb.
If simplified creamy goodness is desired, then I would use heavy cream, though it all comes to a certain degree of subjectiveness, personal preference, and even a palate that may be slanted with what one is used to.
But note that with cream, that boiling pot must be watched, proverbially speaking. So I guess the discussion has come full circle to perhaps making both and tasting, or just what you like, or it may not even matter to you at all...