Both titles use their own replacement SIO routine and so the redirection done by the standard Flash-Kit doesn't cater for this. Secondly, both load data during the game and Koronis Rift can even save position to disk.
There are specific 1Mbit cart images available over on AtariAge:
http://atariage.com/forums/topic/41564- ... art-image/http://atariage.com/forums/topic/42731- ... ges-ready/(use the images on the last two posts for Koronis Rift)
The attached ATR does contain a version of the Eidolon, presumably with the extra data written into extended memory and then loaded in as required.