reyalp,
"The forum runs SMF, it's not unique to CHDK. Generic SMF documentation should be available from google" Thanks Ged and found "Welcome to the SMF Online Manual"
http://wiki.simplemachines.org/smf/Main_Page"Another option to format and partition cards would be using e.g. gparted in a linux VM or live CD/USB. This isn't user friendly..." At this time want to stick with something that is "Beginner Proof" (also called Idiot Proof).
Since posting checked SD wiki
https://en.wikipedia.org/wiki/Secure_Digital and found "Risks of reformatting[edit] Reformatting an SD card with a different file system, or even with the same one, may make the card slower, or shorten its lifespan. Some cards use wear leveling, in which frequently modified blocks are mapped to different portions of memory at different times, and some wear-leveling algorithms are designed for the access patterns typical of FAT12, FAT16 or FAT32.[98] In addition, the preformatted file system may use a cluster size that matches the erase region of the physical memory on the card; reformatting may change the cluster size and make writes less efficient.SD/SDHC/SDXC memory cards have a "Protected Area" on the card for the SD standard's security function; a standard formatter may erase it, causing problems if security is used. The SD Association provides freely-downloadable SD Formatter software to overcome these problems for Windows and Mac OS X.[99] The SD Formatter does not format the "Protected Area", and the Association recommends the use of appropriate application software or SD-compatible device that provides SD security function to format the "Protected Area" in the memory card."
Which is why I am interested to find out about others experience doing this!
Ken