Paladin's smite is a minor problem. In the worst case, all you will lose is the ability to wait for a crit, which in the end doesn't really matter as rest is quite common. Ultimately, this is a minimal change. The only situation where I would really be willing not to complain about reactions like in Solost is when most of them are converted into free actions and only those that cannot work otherwise (counterspell) have pop-up windows. Smite is definitely not among the latter.
