Not sure if these are mods, but:
I added a piece of shock cord that is tied to my foot end zipper and runs up to the ridgeline where it is connected using a mitten hook. I can use my feet to retrieve the zipper to close the bugnet after getting in.
I added few of prussik loops on the ridge line to: hang my head lamp, hang my glasses, hang a bag to put stuff in, tie a shock cord to my pillow bag to keep it from falling to my butt when I get out.
I added a small loop on the zipper side near the shoulder to keep the UQ locked into place. Don't always use it.