How can I make it so on a folder like ‘___ Holiday’ (or something like that) I can only send files on my iPhone but can Send & Receive on my iPad with my PC being the main server for editing remotley when i’m away from home?
Can you post some screenshots to better illustrate the problem in question? It’s really difficult to understand what you mean right now 
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Hi, screenshots might not illustrate my issue correctly. I’ll explain it from my current perspective. I have a folder for an upcoming holiday. The folder originated from my main desktop PC and i’m using Mobius Sync to send footage from my iPad and iPhone. But, I only want to send on my iPhone because my phone does not have enough storage to receive files as well. (I’m still want to receive files on my iPad but its not particularly needed) the only necessary thing is for my pc to still be the main folder or workstation. Let me know if that was unclear. 
It sounds like you want one-way sync. Once you remove items from the phone you want them to stay on the iPad and PC. Is that right?
When I want to do this I setup one sync to the PC with a script on the PC (server in my case) that makes a copy every X hours to a separate folder. Files that are deleted on the phone are deleted on the sync on the PC, but since they have been copied to another folder they will still exist.
A second sync on the PC keeps the second (copy) folder updated with other devices.
As long as you don’t delete items on the phone until you’re confident they have been synced to the PC and copied to the permanent folder then they will be safe. Also be sure to turn on file versioning in Syncthing with a reasonable expiration for the sync folder from the phone.
In my case I have the script hard link the files on the server instead of actually copying, so they don’t take extra space.