Would it be possible to add the ability to set the lister size and position to the Edit Lister Styles
That's more what Layouts are for.
If there's a reason you don't want to use Layouts, you could adjust the window placement via a command that also applies the Style, or possibly via a script that reacts to the Style being applied. But using a Layout is easiest, as the purpose of Layouts is to do everything Styles do with the addition of handling window placement and being able to save/restore multiple windows.
Never used Layout but will have a look at how they work.