Currently the "fuze setting" is governed by the explosive parameter in the ammo config, and there are only 2 states - deletion of projectile on impact, or no deletion. However, currently explosive projectiles can explode multiple times, when they are deflected at shallow angles. This can create huge frame drops in special occasions due to the massive particle amount, is unrealistic and weird to see.
A projectile should never explode when the conditions for deflection are true - because if it was desired that the projectile always goes off, deflecting property should be set so that it never occurs.

Even better would be, if this explosion and bullet-death setting was not controlled by the explosive parameter (which also controlls hit and damage behaviour over distance), but instead by a fuze sensitivity setting.

As a projectile impacts and, it's speed is decreased by some amount (up to stand still). This creates a force. This force is utilized in (basic) impact fuzes to activate the trigger if the negative acceleration, that means loss of speed over a certain time or distance, is high enough.
It would be nice if we could configure a minimum acceleration, or thickness equivalent (for example 30mm RHA steel), for a projectile for it to detonate. This way projectiles could be tuned to not explode in bushes, leaves, cloth walls and other neglectible stuff.

It would also be nice to see an activation delay. That means, once the criteria (acceleration) is achieved, the projectile does not explode immediately, but travels further for a set time amount of a couple of milliseconds, before it explodes and the projectile is terminated.