[Newbie] How to change the size of "selected" border animations?

[SebSnake]

Hi there,

I'm fairly new to WoW addon development, I've given it a try once or twice now, but I don't really like LUA.
As of now, I've made myself some micro addons, like changing one or two frames or adjusting existing addons a little.

What I want to achieve now is adjusting the transmogrification screen.
I'm playing on a 3 monitor setup, so I feel kind of sad when I want to make a new transmog set and the window is so small, the character model partly hidden by the item slots and that stuff. So I decided to rework the transmog frame, so that it can fill my left screen completly (so I make it a 1080p frame ).

This is how far I've come by now:


First, I wanted to use the right space to show more items. But I couldn't find out how to do it, so I just increased the size of the items. But as you can see in the last row, second item from right, the 'selected' effect is not resizing.

Using /framestack, I can see that the name is somehow random.
Currently, it is: WardrobeCollectionFrame.ItemsCollectionFrame.ModelR3C5.119ad4654c0.
Yesterday the last part was something else. Picking a new item for transmog, where the border gets the glowing effect, I can see two of those elements, like
WardrobeCollectionFrame.ItemsCollectionFrame.ModelR3C4.119ac7b1e80 and
WardrobeCollectionFrame.ItemsCollectionFrame.ModelR3C4.119ac7b1e80.Glowframe.

Does someone have an idea on how I could resize these frames?

I'm not sure on how my addon code would help, it is basicly just some event handlers and a single function that uses the ClearAllPoints(), SetPoint(), SetWidth() and SetHeight() functions on all visible elements, which results in what you can see in the screen.