I've installed dash to dock on Pop OS 18.04 (gnome 3.28.1) and it looks weird and misaligned. Is there a way to fix it without having to wait for a new version?

Hi, I guess this is an incompatibility with Pop!_OS theme. I'm not really in the business of supporting all third parties themes as it would be impossible. I usually recommend to point the issue at the theme developers as it should be easier for them (if interested) to tweak their theme.
Have you tried playing with the options in the appearance settings? I'd like to point out that most of these are meant to function with the default Adwaita theme, so maybe disabling some of those might improve the dock appearance and should adhere to the theme author design more.
What is the icon theme?
@micheleg I did. Changing the appearance settings only makes it worse, unfortunately. I'll look into the code of the Pop!_OS theme and contact the devs. Thanks.
@Tarik02 no! I've tried other icon and shell/window themes and it was still misaligned. There's an extra 13px left margin on the ShowAppsIcon, I guess, pushing the whole dock alignment to the right. It's somewhere in the code, not the icon itself.
@belenos, I want this icon theme :)
@Tarik02 It's Pop OS icon theme. You can download it here: https://github.com/pop-os/icon-theme
Also..

This has been fixed at https://github.com/pop-os/gnome-shell-theme/pull/24
Can be closed now, right?
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This has been fixed at https://github.com/pop-os/gnome-shell-theme/pull/24