Apologies, I've been meaning to post this for a while but have had little free time.

Yes, you can cross-compile and remove the fan checks. Below I think misses some required bits (specifically, installing the _linux toolchain from below, setting environment variables and installing the x86 compatibility stuff) but might set you on the right track. If I get time, I'll rerun through this from scratch.

You need:
bmminer-mix
gcc-linaro-arm-linux-gnueabihf-4.7-2012.11-20121123_linux.tar.bz2
gcc-linaro-arm-linux-gnueabihf-4.7-2012.11-20121123_runtime.tar.bz2
zlib-1.2.11.tar.gz

(Google to find)

git clone https://github.com/Zwilla/bmminer-cgminer492
apt-get install build-essential
cd bmminer-cgminer492/
chmod 755 autogen.sh
apt-get install autogen
apt-get install autoconf
apt-get install libtool
autoconf
automake
./autogen.sh CC=/usr/bin/arm-angstrom-linux-gnueabi-gcc NM=/usr/bin/arm-angstrom-linux-gnueabi-gcc-nm AR=/usr/bin/arm-angstrom-linux-gnueabi-ar --enable-bitmain-c5 --with-system-jansson --host=x86_64-pc-linux-gnu
make