I think it is not very practical, since the value of products changes over time, some products have to be consumed quickly, some products degrade very fast, so it means you have to constantly destroy your digital coin with each consumed product, otherwise there will be more and more coins out there without corresponding products
Sure it's practical: you just alter your specific redemption rate to create an incentive for people to buy your product when it's most convenient for you to sell it. As for degradation, when demand for your product declines, so does the value of your specific coin relative to all other coins - this is handled by exchange rate servers, always comparing available buy and sell orders denominated in all coins.
a successful currency system should only ensure that the price of currency stays stable
"Price of currency" makes no sense. Currency shouldn't have a price, as it shouldn't have a value of its own. Only products and services should have a price, i.e. real values should be converted symbolically into currency units.
There are lots of real wealth do not have corresponding currency, because they do not participate in exchange during normal time.
That's with the current system.