Particle size only scales to a certain amount

I want to make it so my particle stays in the centre of a part (using an attachment) while also scaling to that part’s size so it reaches the edges.

The issue I have is that when I change a part’s size, the particle doesn’t scale with it at all/the particle’s size only goes up to a certain amount (10) before it just can’t get any larger. I’m sure the first part is easily fixable via scripting but the 2nd part is what’s getting me.

I’ve tried making it not under an attachment but that only makes the particle scatter around the entire part randomly + doesn’t fix the size issue at all.
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