Want research that prevents other research from being able to be researched.  This was the hope when 7DS was making the Empire to have SITH and JEDI holocrons.  If you research SITH, you can't research JEDI or any of the items that flow from it.  If you research JEDI, you can't research SITH or any of the items following.

I really want a new researchBoolModifiers type that does this.

researchBoolModifiers 1
researchModifier
    modifierType "PreventResearch"
    Type "RESEARCHSUBJECT[X]"

This can also be used for upgradable ships.  Imagine an Advent BC (just has veryheavy armor, composite/veryheavy/heavy weapons, and 2-3 abilities.  This is a special ship because it uses no Advent weapons, but instead is made from reverse engineering Vasari and TEC tech which is applied to the vessel.

In each ship's entity file is the NumWeapons and value 1, 2, or 3 followed by the Weapon tag and 1 to 3 weapons which are assigned by order to hardpoints weapon-0 through weapon-2.  How about NumWeapons 4-6 and instead of Weapon tag, it's actually Weapon-0, 1, 2 and so on with that weapon being available through research.  A ship can have 1-3 weapons, so long as hardpoints are assigned, with the second and third weapon accessible if certain research is completed.  What is not currently possible is to have NumWeapons of 4 or greater and weapons below competing for hardpoint assignment.

This is where the above "PreventResearch" comes in.

If you have Advent BC with 2 weapon-0, 2 weapon-1, 2 weapon-2 that's NumWeapons 6.  Weapon config options are below.  You could go pure TEC reverse engineering or Vasari or go wild with research and mix it up.  If done as single item "RESEARCHSUBJECT_WEAPONRD_PSI_TEC" would mean that it is a PSI research that gives enables TEC weapons; "RESEARCHSUBJECT_WEAPONRD_PSI_PHASE" enables Vasari weapons.  If you research the TEC item, you are prevented from researching the PHASE item and vice versa to avoid causing the game to try to enable two different weapons on the same assigned hardpoints.

Weapon-0 -Autocannon
Weapon-0 -Wave
Weapon-1 -LaserTech
Weapon-1 -Flashbeam
Weapon-2 -Missile
Weapon-2 -PhaseMissile

7DS has a capital with 2 weapons. First weapon has [fireConstraintType "CanAlwaysFire"]; second has:

    fireConstraintType "Research"
    researchPrerequisites
        NumResearchPrerequisites 1
        ResearchPrerequisite
            Subject "RESEARCHSUBJECT_[name]"
            Level 1

The AC/LaserTech/Missile would all have:

    fireConstraintType "Research"
    researchPrerequisites
        NumResearchPrerequisites 1
        ResearchPrerequisite
            Subject "RESEARCHSUBJECT_WEAPONRD_PSI_TEC"
            Level 1

The Wave/Flashbeam/PhaseMissile would all have:

    fireConstraintType "Research"
    researchPrerequisites
        NumResearchPrerequisites 1
        ResearchPrerequisite
            Subject "RESEARCHSUBJECT_WEAPONRD_PSI_PHASE"
            Level 1

With the "PreventResearch" addition, you could have fully customizable ships.

Since it would be stupid just to allow such research without earning it, there should be another 1 or 2 Prerequisite modifiers for research.

Prerequisites
    NumKillPrerequisites 1
    KillPrerequisite
        Race "[name]"
        Kill XX

(where XX is the number of the above race's ships killed before research can be conducted)

or

Prerequisites
    NumExperiencePrerequisites 1
    ExperiencePrerequisite
        Race "[name]"
        Experience YY

(where XX is the experience earned from killing enemies -reflects amount of salvage of enemy gear to reverse engineer their weapons and apply bonuses).  Such reseach items could have multiple levels to give various bonuses to those weapon systems by adding researchFloatModifiers, but you can't have tons of items there -there is a maximum number you can have before SINS glitches out.  Stretching out research to 3 individual items instead of 1 permits easy multiple upgrades to that single weapon.  The AC item could increase Damage, Rof, Range, IgnoreShields just for it allowing one to give separate bonuses to the LaserTech and Missile -also applicable to the Vasari Stuff.

Additional to this is that it could be applied to resistance to weapons used by a race with the addition of something similar to the following:

researchModifier
    modifierType "WeaponRaceReductionAdjustment"
    baseValue 0.000000
    perLevelValue 0.150000
    linkedRace "[name]"

This is another that could benefit from the kill or experience prerequisite type and even the "PreventResearch" researchBoolModifiers so you could only specialize against 1 particular race instead of multiple one.  If you have enough combat experience vs a particular race, you can adjust your shields and hull regen systems to handle their damage better.  So, that addition above could give the Advent a 15% damage reduction vs TEC and/or PHASE weaponry.

So much potential, but possible?  Only IronClad knows, it's their engine.