if I make a custom ipsw through pwnage tool, can I option-click update instead of restore to apply the custom firmware?


it's becoming a pain having to reinstall everything everytime I update.

In theory it should work. However since an "update" will preserve the both the system and user filesystems and there is code in the custom ipsw to make changes in the filesystem organization (and if required size), one cannot be 100% sure that the reorg code will work 100% if the system is in a state other that a clean restore. So it's not recommended.

Do a restore. It takes time indeed, but it's worth as the system starts in a clean state.