Photos.app stalls when downloading all originals from icloud

I want to have, on an external SSD drive, a complete .photoslibrary with original copies of my icloud photos library, which is synced with my phone and my mac. Both have "optimisation" on (the library is ~240Gb, too large for both devices). I want to do this for many reasons, the main one being: "iCloud is not a backup", as repeated many times in these discussions...!

To that aim,

1) I created a second account on my mac, linked with the same icloud account,

2) I created a new library on my SSD drive, and declared it as my systemlibrary

3) I turned on icloud synchronisation, with the option "donwload originals on this mac"

It started reading the content of my icloud library, displayed "Syncing", and after a while (couple of hours?), it correctly identified the 21k photos and 2.4k videos, with downloaded thumbnails. The size of the library was then about 1.2GB.

It then started "Downloading of 23,000 originals", a number slowly decreasing with time. I made sure to forbid the mac from disconnecting, or even falling asleep, so that it would keep on going, BUT:

4) in the beginning, dowloading rate was about 0.4GB/hour (meaning 25(!) days for the full process): bad!

5) 48h later, the library is only 14GB, with 7.6GB for the 1075 downloaded files, only 0,28GB/hour: even worse!

6) and worse of all, it seems most latest downloads were triggered by a manual action of mine: opening a pic, and enlarging it to force the higher resolution.

7) so, it seems my download of originals is completely stalled for all practical purposes!!!

My questions:

9) Is there a way to accelerate the download, other than manually itching the library, or being active on the user account in question (which apparently helps at night, during full moon...)?

E.g. I noticed a file xxx.photoslibrary/resources/cpl/cloudsync.noindex/cloudphotos-1.0.plist which seems to contain interesting parameters... see below. Does anyone know how to put that to use?

10) Is it normal that we have to go to such extremities for obtaining the "normal" behaviour of a cloud "service" paid 10$/month (2TB)?

Thanks for any help or thoughts!

Jean Orloff

PS:

I have my MBP M1 2020 updated to Sonoma 14.7.2;

I am using Photos 9.0 (661.0.111);

I have a fiber connection, with 125MB/s download speed, 30x more than the maximal bandwidth used these past 48h; no known issue between icloud and my isp (free.fr)

PPS: I see limitations in the file below, which make perfect sense:

<50,000 files per day,

<5,000 files per hour

but I am so far below that!!!

On the other hand, there ARE limitations on the FullSize of a picture:

<8,388,608 pixels, e.g. 3200x2400. Not THAT much: is this really the "original"!!!

cloudphotos-1.0.plist

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>configuration</key>

<dict>

<key>client.request.throttle</key>

<dict>

<key>forget-after</key>

<integer>3600</integer>

<key>give-up-after</key>

<integer>1800</integer>

<key>start-after</key>

<integer>2</integer>

<key>wait-at-least</key>

<integer>2</integer>

<key>wait-at-most</key>

<integer>60</integer>

</dict>

<key>compute-state.upload-task</key>

<integer>2</integer>

<key>feature.version.computesync.download</key>

<integer>2</integer>

<key>feature.version.computesync.upload</key>

<integer>2</integer>

<key>feature.version.duplicateprocessor</key>

<integer>1</integer>

<key>max.days.inRecentlyDeleted</key>

<integer>30</integer>

<key>max.num.photosToImport.daily</key>

<integer>50000</integer>

<key>max.num.photosToImport.hourly</key>

<integer>5000</integer>

<key>max.num.recordsToUploadPerBatch</key>

<integer>200</integer>

<key>max.num.resourcesToDownloadPerPush</key>

<integer>30</integer>

<key>max.num.resourcesToUploadPerBatch</key>

<integer>8</integer>

<key>photo.derivatives</key>

<array>

<dict>

<key>pixels</key>

<integer>172800</integer>

<key>type</key>

<string>thumbnail</string>

</dict>

<dict>

<key>pixels</key>

<integer>3145728</integer>

<key>type</key>

<string>preview</string>

</dict>

<dict>

<key>pixels</key>

<integer>8388608</integer>

<key>type</key>

<string>fullSize</string>

</dict>

</array>

<key>refresh.interval.seconds</key>

<integer>7200</integer>

<key>video.derivatives</key>

<array>

<dict>

<key>pixels</key>

<integer>921600</integer>

<key>type</key>

<string>PosterFrame</string>

</dict>

<dict>

<key>pixels</key>

<integer>230400</integer>

<key>type</key>

<string>PosterFrameThumbnail</string>

</dict>

<dict>

<key>type</key>

<string>720p</string>

</dict>

<dict>

<key>type</key>

<string>360p</string>

</dict>

</array>

</dict>

<key>lastUpdate</key>

<date>2025-01-05T17:41:37Z</date>

</dict>

</plist>