Yea Fat16 with 32 KiB cluster size = 2GB. E1 card are probably sd micro standard before the sd micro 2.0 standard was released.
It might be possible to find pre sd 2.0 standard 4GB cards that use Fat16 with 64 KiB cluster sizes. I imagine the 32 KiB cluster size might be a firmware restriction.. maybe the java player can still use pre sd 2.0 Fat16 cards formated with 64 KiB clusters?
Yes, you are right. Standard used in e398 and E1 is older, since e398 is from 2003. and E1 from 2004-or-05... You can use up to 2GB (thats been tested so far) and you have to format it in other Motorola that supports 2GB cards (V3x for example), cant be done on the PC.. And then like ypu mentioned, only Corelets, Midlets and ELF apps can read the card... Phones system (going to Multimedia>sounds>from trans |example|) wont read it... If its beyond the 1st GB if I remember good.
Besides that there are some e398 models that dont even read 1GB (like my brothers phone). And in most 1GB works normally (like in mine).
Cheers and welcome to the forums