Shorter development cycles? Are you kidding? The shorter the better. Even if the changes are few, someone might be just waiting for that new feature (like me waiting for dxf export). If you can handle the extra work - please release as often as possible. This will keep people interested - hey look the site is alive and kicking.
Maybe you can use the philosophy of stable and unstable branches. You could offer more than one version to save the file in, a stable or old and a unstable or test version. The test version would be the one with the extra information in the header or somewhere about who built it in what environment. Maybe you could ad a notes section to the file. If I have issues with a certain file one could add some descriptive info. (Like this file wont load into version soandso). The normal file version may not need this and could save the space.
I spent some time on the Trackdraw project at http://www.trackdraw.org
and learned that new versions often broke things that had worked before (svg export seemed always to be critical). Yet a live forum and frequent releases seemed the best way to solve problems.
Addressing the start of this thread maybe a roadmap such as here http://dark-oberon.sourceforge.net/?page=roadmap
might be usefull. It may give the interested user an idea of what is happening and were you plan to go when.
I had requested a loader or wrapper for the portableapps.com menu here http://portableapps.com/node/11172
maybe you could help with an in between version suited for portability or at least document where Cademia stores what information or even host a special portable usb key friendly version on your own site.
Maybe the plugins at http://www.litecad.com/
could be usefull?
Oh somewhat offtopic but have you read the entry about Cademia here? http://de.wikipedia.org/wiki/Diskussion:Liste_mechanischer_CAD-Programme#CADemia
There's quite a lot of issues addressed there
As it seems you might want to investigate the possabilities of skins for the GUI. A CAD-profi version like you already have, a grafic-design guy version with a maximum of mouse input, a schoolboy version with lots of icons and a gardeners version with a plant library... oh well halfway kidding... nevertheless skins are cool.
maybe next time I should split my posts...