It's not working for myself either. I've subscribed, but can't find it on the mods list to install.

for me I just had to wait a bit then it appeared in the mods list

Hi, sorry for the delayed reply, I'm not really checking the steam comments often. I've put the 7z archive on Dropbox, you can try downloading the collection directly:
https://www.dropbox.com/s/g6vxea1qmn77s43/tops%20collection.7z?dl=0

To add it just extract the archive to "PATH_TO\SteamLibrary\steamapps\common\Dungeon Painter Studio\data\collections\"

UPD:
I just got a message from Dropbox that my download links were disabled due to the fact that "they generate too much traffic". I have a free account and I don't have much shared files besides this collection for DPStudio. Of course with the message there was a link to "upgrade my account to paid one" to get link working again... So I hope that Dropbox burns in hell with their policies and "subtle" attempts to get people to pay them.

UPD:
You can download collection from here (remove spaces from link):
mega . nz / file / GFgEBRoa#GMYT2Spm7Q3VZ-kJKp9vYQpZA9g3PnlhUlcfbCC5Xd4

Is there a way to not have them in a .7z file?

Here's a ZIP-version link if you still need it:
mega . nz / file / GVJ1FYCT#Nd7Eq_eQ9yaTHIgEVA5L6OeVspjJNOV1cG23DfG42ds