4 of 7 added 78 characters in body

Is this homebrew “Throwing Weapons Master” feat balanced?

I'm trying to create a Fighter/Warlock character based on Kratos in the newest God of War game, who wields a two-handed axe which he can throw and summon back to his hands.

Pact of the Blade Warlock covers summoning the weapon back, but I would like to be able to throw something more substantial than a hand-axe.

My DM has agreed to let me take a custom feat if I can show that it is reasonably well-balanced. Our game is pretty casual and I'm more interested in flavour than pure efficiency but I would like to know if there is anything game-breakingly good or bad about the following feat.

Throwing Weapons Master
You can throw any melee weapon that you have proficiency with as if it had the thrown (range 20/60) property. Weapons that already have the thrown property are unaffected.

Is this feat over (or under) powered? If so, how could I fix it?