Yes, my 4171 host/heatsink combo will also fit a full length AixiZ module using 2 X RCR123 rechargeable batteries. Which are a total of 8.4 volts at full charge...
This is a good voltage for a red build using the rkcstr driver. And will also power a blu-ray, but the blu-ray/rkcstr build would soon start to drop out of regulation as the batteries start to drain.
The rkcstr documentation says that your supply voltage needs to be a minimum of 2.25 volts above your demand. So if your diode needs 5.5 volts or more (8X), then you need a minimum of 7.75 volts on the supply end. And it would not take very long at all for your fully charged (8.4) batteries to drop below that voltage. Then the laser would still be working, but just not at the regulated current setting. So if you are thinking blu-ray, you may want to consider the 3405 host, using 3 X 10440's... (which are now available with protection)