Yes. I have made many soundboard/martix recordings with a number of mics. (FWIW, I would look into other mini-cardioid alternatives to the Core Sound Cardioids, in particular offerings from Church Audio, Sound Professionals, and Microphone Madness.)
I always bring a couple attenuator options with me - I bring a pair of -12dB RCA barrell attenuators for higher quality attenuation if I expect to need it ahead of time. (Although maybe I don't really need attenuation - in theory the DR2D specs at max input level of +6 dBV = +8.3 du on the line input versus a nominal +4dBu pro line levvel -- but definitely in practice some boards' line outs will clip the line input if the rec level is set to 100 and I'm always leery of attenuating via adjustments that may be in the digital domain; and some peaks may exceed the nominal pro level). I also bring an inline headphone volume control I can always insert in an emergence if I need to reduce levels on the fly (the one big drawback to the DR2D for board feeds in the dual recording mode is that in dual mode you can not adjust the line input's rec levels on the fly, only the mic in). In practice I usually either know the board at a particular location and can set levels/insert attenuators as needed ahead of time or I can set levels during the soundcheck, so it's usually no big deal.
Some examples of matrices I made with the DR2D and various mics, and my recollection of attenuation need (or lack thereof):
Warren Hood and the Goods: SBD + Audix M1290c>Littlebox - Worked with the friendly soundman during sound check to get the right levels for line-in at 100. As I recall, his default starting position on the output levels put my peaks at ~ -12 dB at line in / 100, no attenuators.
http://homepage.mac.com/satterwill/whood2010-05-24d2t05.flacJames Nash and Friends SBD + AT822 onstage - Had a variable line out on the soundboard, dialed in levels for line in 100 with no attenuation
http://homepage.mac.com/satterwill/nash2010-08-28d1t05.flacWaybacks SBD + Sennheiser MKE40s > 9V Bbox - Ran line in at 100. The soundman had told me to expect a pro level signal, but during the sound check it was hitting -12 tops so I rolled with no attenuators. Track 12 was minor clipping in one channel at the crescendos, but thanks to mixing in the AUD signal in post the flat tops get rounded over. Can you hear the clipping?
http://www.archive.org/details/waybacks2010-11-20.mtx.flac16fInfamous Stringdusters SBD + MKE40s (no Bbox, plug-in power) set 1 and Audix M1290hc > Littlebox set 2. This one I had no soundcheck. Ran line in at 100 for the first song with no attenuators. Too hot for comfort so I swapped in the headphone volume control before the 3rd song. Can you hear a difference?
http://www.archive.org/details/isd2011-01-12.mtx.flac16fNashvillains SBD + MKE40s > 9V Bbox Board feed was line in 100, peaks were ~ -12 dB
http://homepage.mac.com/satterwill/nashvillains2011-02-11d1t02.flacLane Murchison and James Nash - this was a fun one. MKE40s > 9V Bbox, plus one channel of line out from the PA mixer for acoustic guitar and vocals plus one channel taking the dynamic mic output from James' guitar amp (electric guitar not routed through the PA). The mixer was really hot and needed a bit of attenuation with the headphone volume control (although levels were set to 100, the DR2D might have adequately attenuated it), which left the dynamic mic signal from the guitar amp pretty low, but it boosted OK in post.
http://homepage.mac.com/satterwill/lane+james2011-02-13dtt08.flacWalter Strauss SBD + Audix M1290c>Littlebox line in at 100, no attenuators, peaks were -12 or lower I believe
http://homepage.mac.com/satterwill/wstrauss2011-05-01d2t10.flacWake the Dead SBD + MKE40s (no Bbox) - line in at 100, no attenuators, peaks ~-9 dB
http://homepage.mac.com/satterwill/wtd2011-06-03d1t08.flac