It's worth noting there's not too much point playing with the F proxies - they are generated by scaling the H proxy up, so they contain no more info or detail than the H ones. This is according to posts on reduser, eg.:
http://www.reduser.net/forum/showthread.php?t=12832&highlight=F+proxies
Indeed, Stuart and Deanan from RED have explicitly said not to touch the F's until they are properly supported.
Hopefully this (and the log and transfer half-size limitation) will disappear in the legendary build 16. Along with all wars and the boogeyman.
;)
Ben