How to use LAN 1st before cloud storage when syncing cloud?

I want to setup the capability to edit remotely on a project that has 9 months of footage. I currently work on site accessing material through a shared storage device on the local network infrastructure. A couple of weeks ago we set up the cloud storage and put the project on to the cloud and also had it generate proxies for all the shots and sync those to the cloud.

Theoretically I could plug an SSD in at home, log in to my Blackmagic account which has been added to the project, and click sync and watch that drive gradually fill up with all the proxies from the past 9 months worth of media. The proxies have crunched the size of the project considerably from some 50TB to just under 1TB, but 1TB is still quite a lot over the internet and especially so on my home internet connection.

I want to copy all the proxies to the SSD while I'm here with it at work from the local network storage and then work from the cloud at home with any new proxies that get added to the project on-site or any new material I might import or generate from my end at home, sunc to the cloud storage. This has proven hard to figure out.

1. My first problem was that I could find no easy explicitly setup method for doing this via any of the cloud options or settings in Resolve and no easy way to specify the copying of just proxies and not original media. Eventually I figured out I could do a project archive which includes the ability to specify that so I did but I was concerned exactly how this would work when I got home and how I'd tell Resolve on my end that this media from the project archive on the SSD was the media to check against when seeing what state of synchronisation my system was at, so it would know not to download any proxies unless there were new ones added after yesterday when I did the archive.
   
2. My second problem is linking, as in, unsurprisingly when I open the project at home it doesn't know the media it's looking for is on the drive connected to the system. Theoretically that's an easy solve by just relinking the media, but as this is a shared cloud project, how do I know that act of relinking isn't considered a change to the project just like making an edit on a timeline would be and which would be sunc to the project file here on site? I don't want to knock all the media offline at work, that'd make me very unpopular. I've heard murmurings that it doesn't do that, but it sure doesn't say that specifically anywhere including in the manual. It seems a reasonable bet it doesn't do that but it's just so unclear.
   
3. I thought perhaps I might solve both problems by setting the 'project media location' in the cloud settings to the SSD root, or even various (I tried several) of the subfolders of the project archive, this I hoped might convince Resolve to look there for the media to both bring it online at my end without an explicit relink and also look in that location for the media when assessing the state of sync between my machine and the cloud so that if any new material is ingested on site it'll flow my way and if I generate any new material on my end it'll flow back to the cloud for the folks on site. This didn't work, the first time I tried this, it told me the project media location was set to a drive that has no more space. I don't know if this is a glitch, or an odd way of phrasing that it doesn't have enough space (rather than there being no space) because all the proxies together are just under about 700GB and that leaves the drive with 300GB of available space so it obviously isn't the case that it has "no more" space but it does lack enough capacity to download all the proxies for the whole project if that was the goal. However, that isn't the goal, I wanted the action of setting that project media location to allow Resolve to see that the reason there's so little space on the drive is because it's full of the very media it's blindly trying to download!
   
4. I tried a lot of different things and then finally tried doing the exact same thing again as in the previous point only this time, instead of claiming there wasn't enough space, it actually tried to do the sync. It took a long time and showed me the mac beach ball so evidently it was working hard on something, I had fingers crossed this was because it was actually checking through 9 months worth of material against the contents of our cloud storage to compare everything which would understandably take a while. I figured I'd let it do it's thing and it actually seemed to create some media in the specified path, in that it actually downloaded a small number of proxy files. This wasn't really what I wanted because I should have ALL the proxies anyway, but I was curious what it would do. I let it go overnight to see what'd happen. When I got to it this morning, nothing had progressed it evidently actually had crashed only a few seconds after I initiated the sync, in any case it looks like it was trying to download everything rather than properly checking what media was already there like I wanted.

To reiterate, I want to work with just proxies, remotely, using the cloud storage and cloud project options, but I want to essentially kick start the process of synchronising the proxies by leveraging the LAN here on site first, so that they're ready quickly and don't tie up my internet connection at home and then work entirely in the intended way from then on with media sunc both to and from my end, remotely, using the internet. Is this possible?