It all sounds good, but what is the function of COVAL itself? if it has no function because as you said you can send other coins, so the value of COVAL is not important and it will always stay very low, below 1 cent........
As of the last update on this matter People will be incentivized to use COVAL because of the big discount on fees as compared to other forms of payments.
Based on previous information provided on Telegram and Riot (subject to change) using and holding COVAL will secure other “goodies” to the user (giveaways, airdrops, etc...)
Nothing is definitive yet, but this system, or a variant of, has been successful for other projects (such as Binance BNB).