Those are interesting thoughts with regards the increase in power and speed. For whats its worth this might also be worth considering. (I am trying to keep this simple!!)
1: UV energy is the energy that is principally used to effect the cure of most types of the printing resin (In this case energy around 405nm wavelength)
2: Daylight energy (from around 430 - 650nm) can be used but the chemicals used to create the cure has a whole range of issues in a 3D printing application compared to using the chemicals for a cure in the UV range.
3: LCD screens are generally protected against UV transmission, this in practice means that only a very small amount of UV energy will pass through them In practice this means that at 405nm only 0.5 - 1.5% of the total light energy is passed through the screen. At 450nm that figure increases to around 40%, at 395nm it decreases to around 0.002 - 0.0005.
4: 405nm is normally accepted as a reasonable compromise that is accepted as the target working wavelength for cure of a photo-polymerised resin with a LCD based mask.
5: If we look at moving the wavelength towards visible light range (known as Redshift) then the issues with the chemistry of the resins (much worse print quality and material physical properties (increased brittleness and shrinkage) offset any gain in the amount of power transmitted through the LCD mask.
6: UV power in 3D printing is usually measured in mw/cm2
7: Electrical power (consumed by the light source) is the figure normally quoted by the printer manufacture NOT the amount of UV energy at the build area (which is what is needed to effect the cure). There are many factors that influence that, including the exact type of crystalline structure of the LCD screen, the type of filtering and the working temperature of the LCD screen.
UV energy slowly but surely destroys the LCD screen crystalline matrix (that is why it has filtering to protect it and why the screen manufacturers say don’t expose the screen to direct sunlight) In 3d printing the LCD screen should be regarded as a consumable, it will deteriorate with repeated exposure to the UV light source. The greater the UV power then the quicker it deteriorates. Most LCD mask screens in a 3d printing application have a workable life of between 200 - 600hours lifetime.
That life time is only achieved IF the UV power (at the build plate / layer) is between 1 and 2 mw/cm2. Anymore and the screen life dramatically reduces. In fact at power levels of 20mw/cm2 (that is power at the build plate / layer) then the screen life can be as little as 10 minutes - BUT that requires significant UV power to the back side of the screen, its the UV power that has passed through the screen which is what we use for the cure of the resin.
A great enemy of LCD masks is also heat, most screens transmit less power as they get warm. A surface temperature of 85c and above causes irreparable damage in the short term. Above 115c causes failure, so cooling is very important. Normally the increase in electrical input power to the light source increases heat.
If the amount of photoinitiator (the chemical that starts the cure when UV light is applied) is increased in the resin then the cure will generally be faster, but so to will the amount of shrinkage and heat generated as the resin cures, so as you can see its all a compromise to try to get screen life, effective cure, and good mechanical properties of the cured part. The best cures (best properties) tend to occur with lower levels of photoinitiator in a resin. That requires greater UV power to make the resin cure.
Super fast cure times are relatively easy to obtain at the expense of material properties, but as said before its about a compromise. If you only pay a few hundred dollars for a printer then accept that the easiest thing to compromise is speed of cure.and your cure times are going to be slower than say a laser based SLA or projector based DLP printer - both have significantly greater UV powers (at the build layer) available for the cure
