alt64 is older than the cloned ed64v1, the sram defect was added in versions after it's release, but i can't remember exactly the version number.
and yes it is working but sram games like oot of f-zero x don't save... the good ones. ^^
there are no sd2snes clones per definition, 'cause it's an open source project from it's beginning.
as far as i can remember, the first boards were manufactured by ikari_01 himself in a small batch.
it's not that i like to sit on source code, in fact sharing the source with parasyte resulted in the working gs core.
and i shared some info with krikzz via pm, too - like 64dd loading, aleck64 loading, ultracic II x105, dezaemon sram768 mapper.
i just don't see the point in improving the clones, with an advanced open source menu
to end this discussion
maybe you could just ask krikzz about this issue, if he think it's a good idea i can update my github repo.