It's a pain, but if you save your custom selection as a vectorscript with additional criteria that corresponds to the change you are making to the PIO, you can get through your changes a little faster by using the vectorscript, making your changes, and then running the script again. The additional criteria will make sure that the ones you have changed are not selected, and instead the next PIO in the wall is selected. Eventually the script will not select any PIOs- then you are done.
It's not perfect, but it is faster than doing each one individualy- especially on large projects
-P