Option for old notification style and layout?

how do I change the upper and lower margins in the notifications? I liked it more with the more intense borders and smaller margins, could we get an option for this?

additionally, I noticed that the notification icon is on the other side now, can there please be a setting to swap the position?

If you’re talking about the layout that Plasma used like 5 years ago before the current design was implemented, then no, there is no user-facing way to get it back. The current layout has been in use for several years though. Did you just update an ancient installation or something?