wimboot & winpe - assorted questions

[jpwise]

Morning all, just been playing with wimboot - awesome looking utility guys. Definitely fills a gap in the network booting vs memdisks area.

[links for the new]
http://ipxe.org/wimboot
http://ipxe.org/howto/winpe

Managed to get a selection of 32 & 64bit Windows Recovery Environment Wimboots setup for workshop use (and avoiding the memdisk issue on v.low memory machines).

But.. onto other ideas. Some of the utilities we run in the workshop are PE based and subject to frequent change - input files need changing on an almost weekly/fortnightly basis.

Historically we've run the utilities from USB flashdisks running PE, and just updated the files manually within the USB filesystem, without the need to rebuild the wim file. Utils are command line/batch based, so once you find out which drive letters assigned to the usb drive it's just a matter of changing drive/dir and running the batch.

Firstly - can you think of any methods to achieve a similar use case using an ipxe booted winpe image?

Turning the idea over in my head I'm thinking along several angles.
1) include secondary wim (or other?) file in wimboot process that's mounted as another drive letter - not sure if this is possible?
2) include network drivers in wim file, followed by an included batch file that loads network & downloads updated files - would require injecting network drivers into the wim on an as required basis, but these change less frequently than the input files do.

Other ideas outside the immediate scope of the issue include if there's any way to pass variables to the winpe environment during boot. One thought is to embed a selection of batch files into various indexes within the wim file, but as far as i can tell wimboot doesn't support index selection as yet.
There is some info at: http://forum.sanbarrow.com/viewtopic.php?f=85&t=15 relating to arbitrary index selection which could be used, but it would require more research to implement and potentially custom sdi/bootmgr files.

Ideally it would be nice to have one base pe image that could then go off and load secondary programs depending on what variables it's passed, but realistically I don't know if this can be achieved, so the more immediate project is to determine the best way to load high change files for use with a base PE image - _without_ rebuilding the PE image every time.
Right now from what I've researched, I'm leaning towards #2 as above and loading network drivers + downloading a zip file or similar to uncompress and execute. Then it's just the zip that gets updated as required.

Thanks for any suggestions offered.

Thx.
Jp.