I consider no-UI, no-ITU variants to be automatically unusable. ...
Very much disagree. ITU is an automatic hullmod for all non-SO ships because it is deliberately overpowered and balanced by rarity. UI however is a judgement call and it depends on the rest of the fleet composition and expected enemies. Between the range and OP costs, UI sacrifices a lot of combat power for speed. Sometimes that trade is worth it, sometimes not.
Frigates almost always should have UI because, with a few exceptions, their only defense against fighters is speed.
Against early game fleets with frigate spam? UI on everything because the player's ships need to be able to avoid flanking by enemies.
Player has lots of fighter cover? No UI on destroyers - flanking/interception/harassment work are covered by other elements and they are free to become more dedicated gunships.
Fighting capitals/stations? Cruisers and Destroyers should not have UI because they are already faster, but the speed increase does not overcome the lost range in terms of approaching a target to firing range without being overloaded.
In the case of beam sunders, UI is almost always worse than UI because the base range is so long - the speed increase is not close to making up for the damage lost on approach. Same with HVD/Mauler Hammerheads to be honest. Railgun/Heavy mortar hammerheads do great with UI however.
On otherwise similar variants ITU vs no-UI, no-ITU is absolute advantage for ITU side. AI may be not quite there, but assuming AI was as good as player at flux management, did not make range management mistakes and no piloting tricks by player this would be an unwinnable scenario (you can approach by armor tanking on zero flux boost, but doing so stacks some disadvantage, so this alone is unlikely to bring victory).
Or at least this is the logic for player-piloted engagements. In AI vs AI duel both cases are definite loss for non-ITU AI.
Might as well simplify my rule to: don't use AI-piloted DEs if ITU is unavailable.
I don't agree with Capitals part too. Extreme example - vs a Paragon UI would reduce approach time (their range - your range/ speed difference) much more than a bit of range.
Beam Sunder without both ITU and AO is a too flawed variant to be practical, so I guess whether it has UI or not is a moot point.
... In fact, after extensive testing I see no reason to use AI Sunders ever. All strong variants rely on fine range control, flux management and HEF syncing - things that AI can not do well enough. Any Sunder gets stomped by same optimal Hammerhead variant in AI vs AI, because it's win tactic is as simple as "activate AAF and enjoy the fireworks".
Pity, considering that TL + ITU + Optics Sunder beats any Hammerhead completely one-sidedly when piloted properly.