As per title. What general or individually small changes might be possible for dungeons that could nonetheless improve them? Any ideas?
My $0.02, in ascending order of required effort (for hopefully increasing reward):
1. Remove Tank Mastery but only reduce the damage of the most powerful tank busters (ones that might otherwise newly one-shot under the same level of active mitigation). This gives at least gives the chance of some GCD heals shaking up healers' filler-attack-spam.
However, Interject now initially Silences and Pacifies for 3s, both suffering from DR while the interrupt remains unaffected and will always interrupt any attack normally stoppable by either status, and Low Blow now always also interrupts attacks on enemies that are innately immune to stun, and both have had their CDs reduced to 20s.
2A. Reduce the maximum item level of most content to roughly that of their rewards but nerf all mob's HP faintly in turn.
--and/or--
2B. Minimum Item Level Runs now increase drop rates (including that of gil, exp, tomes, etc.) according to your stats reduced by the ilvl squish for personal drops and according to the party's average stats reduced by the ilvl squish for shared drops (gear, mounts, etc.).
Simultaneously, "Variant" runs may now use the matchmaker, seeking out others with the same settings for the given content. A new checkbox has been added (slightly shadowed, slightly smaller, to the right of the main box) to queue for one's chosen variant of each content or roulette type. This can be done simultaneously with a regular queue. Upon login following this change, this will be noted via a new Patch Information pane and the "variant" options will be set to Minimum Item Level.
So, no scaled costs by having to adjust individual dungeons (as none hit hard enough to OHKO a tank) and just a bit of tuning adjustment to Ultimates and certain Savage fights in exchange for positive gameplay shifts and increased optionality both in and out of dungeons.