not going to happen, you'd need to either recompile AsbestOS (or whatever version of it you're using) from source or under linux mount the .img file as a loopback to a folder and manually edit the bootscripts (different depending on the distro you're using) to switch the video mode back to a sd resolution during boot.
no you don't, all you need to do is set the ps3 video mode to either 1,2,129 or 130. just for some reason the idiots set it to boot at 3 (720p bordered) so you wont even be able to see the prompt to issue the commands needed.
And the kboot cmd for booting the image is hardcoded into asbestOS (and kmeaws version) so you can't change the parameters without recompiling. Editing the img will work (by switching to a SD mode during postboot) but you won't see any error messages if it doesn't work and editing the img file is a pain.
if you're upto it, or under linux on a pc or vm mount the img file as a loopback which will give you access to the files inside so you can just change it in there say for the bashprofile or whichever boot scripts your distro is using.
But I don't think kmeaw ever released his source for his modded version or detailed the changes he made from marcan's (probably just the fw offsets though)