You remind me of the old times.....
i used to make some start up sequence files ,and execute them.
if i remember correctly i put whole path of each executable
one under the other.
the amiga would run the program,waited to complete ,and then continue to the next demo.
i did not encounter the above memory issue.
i was using AGA 1995 era demos.a quick test would be to run each demo ,and see if at the end,the amiga will return to the workbench screen.