So I've been thinking about this a bit more.

http://web.mst.edu/~cottrell/Issues/LCDprojector.pdf

If you look at the first picture in the above document, my guess is that you would remove "A" and replace "B" with a mirror instead of the dichroic filter.

http://www.3lcd.com/explore/dichroic_prism.aspx

Also, the prism that joins the RGB streams is made from dichroic filters. So that would need to be removed also.

Lastly, the polarizing filters before and after the lcds, well those are specific for each colour, and it is my understanding that they also act as filters to remove unwanted wavelengths (like UV) for each of the 3 colours.

So I would replace the polarizers on the center led with generic lcd polarizing film instead of the specific colour polarizing film used in these projectors.

I haven't heard definitively that generic polarizing filters will filter UV, although it is my understanding that some can (like perhaps the ones normally used in 3LCD projectors). People are making printers using large lcd panels for bottom up builds with UV led arrays to replace the backlight, so I am guessing this would also work?

These mods seem straight forward to me. I don't see why they wouldn't work well. I was looking for a cheap setup to try this out on and do some tests before buying a 1080P one. No luck in finding one so far.

Thoughts?