Link to gigamem 3.12 if you want to try it :-) remember it only supports what's in the gigamem's database so you'll need to add quake2 to the database. Although I don't think that's going to work.
http://lilliput.amiga-projects.net/Files/GigaMem%203.12%20(199x)(Relog%20AG)%5bWB%5d.zip
Unless the Amiga software is documented to support virtual memory it should not be used with virtual memory. There are runtime restrictions to virtual memory access and unless software is designed to support these restrictions they are likely to crash violently.
