I do kinda agree with Kalrakah that the Elf's racial specials are much more unique and powerful than the ones for the other races. I suspect that Larian had a hard time coming up with unique and balanced bonuses for each race.
Pretty sure Encourage stats already scale with levels.
And adding a heal on top of it would be way too OP. Increasing constitution already provides some healing.
If Encourage already scales, then that part is no problem.
The heal I suggested is just 15%. As in 15 health for every 100 the player has. I don't think it would be OP given how hard enemies hit in this game. It would add strategic value - should you use Encourage at the start of combat for a buff, or save it for later when you might need healing. The idea is that the health heal represents a morale boost and encourages people to fight.
I will concende that perhaps the combination of scaled +CON and +15% might get to be a lot later game, so that would be a case for scaling the buff back somewhat.