Martial Variant to War Caster

[H Savvy]

tl;dr I need help finalizing a feat conversion for war caster

I'm trying to work with my DM on updating the War Caster feat to provide benefits to non-casters. This is primarily so it can dovetail with Crossbow Expert.

In early discussions with him, I was trying to see if he’d allow reloading a crossbow while holding a shield in the other hand, which, technically is not allowed by RAW (because of the free-hand requirement on the Ammunition property). He decided not to allow it and I went along with it (because while I thought it was cool, I could live without it). However, he did say that per this answer on the RPG.SE he would allow it if I took the war caster feat.

Now, having discussed it further (I wasn’t interested in war caster because I wasn’t interested in being a caster) we’ve agreed to re-skin War Caster for ranged weapons. Most of it’s pretty easy, but the Concentration checks don’t seem to have an obvious analogue. So... my question is this:

Can you help me fill in the blank on this homebrew feat conversion?

From:

• You have advantage on Constitution saving throws that you make to maintain your concentration on a spell when you take damage.
• You can perform the somatic components of spells even when you have weapons or a shield in one or both hands.
• When a hostile creature’s movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, rather than making an opportunity attack. The spell must have a casting time of 1 action and must target only that creature.

To:

• _____________________ ?
• You can reload weapons with the Loading property even when you have a weapon or shield in your off hand.
• When a hostile creature’s movement provokes an opportunity attack from you, you can use a ranged weapon to make an opportunity attack against it.

Possibilities we discussed:
A small boost to initiative (+1 or 2)
Extending the range you threaten to 10 or 15 feet
Some shield-based bonus, perhaps to dex saves a la shield master...

Thoughts?

[demonslayerelf]

You ignore disadvantage from a creature being prone.

When rolling with advantage, also roll damage with advantage.

You may use one of your attacks to reload a weapon with the loading property, rather than a bonus action.

[Grod_The_Giant]

You ignore disadvantage from a creature being prone.

I like this one.