I found out about that last year and went out and bought a set of Schuler filters from Astrodon for my DSI Pro, but other things have been eating at my time. Once Venus is back as an evening object, maybe I can get into it.
I think they scare people off by requiring them to calibrate their images. Flats and darks on top of non-visual filter requirements chases away the casual imager. They also state you need an 8" or larger scope. ED80 need not apply.
plus you need to submit in uncompressed tiff or fits files (big download)
i come across all sorts of freebies (submit all your personal details sign up for who knows what and more jumping through hoops) i can only say no thanks....
people want your help in their projects then get all antsy about the details.... again no thanks
Well all the finer details are needed because it is contributing scientific data that will actually be used...what for i have no idea....
I guess they do the long winded thing to make it harder for casual users (to weed them out) and more so for those who have the equipment and the know-how on this sort of imaging.....sort of free sub-contracting isn't it!