Just make a mod that reduce flight time but grant better application OR more missile speed. Hell make it similar to a TC if you want with different scripts or 2 entirely different mod so a trade off has to be made at the fitting screen.

Seeker optimiser
(insert fitting cost here)
Missile explosion radius +10%
Missile explosion velocity +10%
Missile flight time -15%

Rocket engine overfeeding system <---- this name is sooooo bad
(insert fitting cost here)
Missile flight speed +10%
Missile flight time -15%

If missile ship trade damage potential for missile speed, they would still not get taken in incursion fleet because their dps would be to low to justify them being there. People would still need as many BCU to bring similar damage level to what gets in fleet. They would use leftover low/mid slots for application like gunnery ship do.

At a glance I would say that the numbers are arbitrary, however your point is valid and possibly the scripted module would allow you to choose an unscripted bonus of 5% to each, or scripting to receive 12% to one.
In my opinion, the important thing is that people can agree on the base concept of a passive low trading speed for flight time, and an active, possibly scripted, mid that allows you to affect your application by trading tank. If players can agree on this then we can proceed to crunch numbers and present a consolidated front to CCP and push for the change as a majority. Doing so would also mean that when the changes came out they would be received much better than if CCP just ran out another RLML system fiasco.

As for Defenders, there is already a module for them so why create an entirely new one? I would much rather see the existing module/ammo fixed to take advantage of utility highs.

Cause it makes total sense to compare Large guns to medium missiles...

I think we need better analysis of the numbers.

Altering the explosion Velocity and/or Radius may have significantly different effects on missile damage application (compared to changing tracking for turret damage application).

Damage Upgrade module, T2 (such as Gyrostabilizer, Heat Sink etc):
GÖª The 1st T2 Damage Upgrade module increase damage with +23.5%
GÖª The 2nd T2 Damage Upgrade module increase damage with +20%
GÖª The 3rd T2 Damage Upgrade module increase damage with +13%
GÖª The 4th T2 Damage Upgrade module increase damage with +6.5%

Tracking Enchancer, T2:
GÖª When Angular velocity = 25% of your Tracking: +9.5% more tracking is the same as +1.1% damage
GÖª When Angular velocity = 50% of your Tracking: +9.5% more tracking is the same as +4.2% damage
GÖª When Angular velocity = 75% of your Tracking: +9.5% more tracking is the same as +9.5% damage
GÖª When Angular velocity = 100% of your Tracking: +9.5% more tracking is the same as +16.6% damage

In comparison, a 10% decrease in explosion radius has an 11% increase in damage to a slow target.

A target must be moving faster than the a threshold to receive a reduction in damage do to speed. This threshold is easily calculated as Target Size * (Missile Explosion Velocity / Missile Explosion Radius). The last two terms are both altered by by 10% with this module. A 10% increase in explosion Velocity with a 10% decrease in explosion radius is a net 22% increase, meaning ships need to travel 22% faster to reduce missile damage.

To sum up:
Your module is an 11% increase in raw damage, and increases the minimum velocity to reduce damage by 22%. It doesn't stack with target painters or Ballistic Control Systems either.

I have a feeling your numbers are out of line, especially since reducing missile dps is much more difficult than reducing turret dps!