When uploading full media library nextcloud takes enormous size of iPhone storage, creates a lot of duplicates, files with wrong date and 0-sized files

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Steps to reproduce

1. Large iPhone media library (mine is 14k photos ~124Gb)
2. Start uploading full library
3. Note: this library is auto-uploaded over several years, so almost all files are already on the server.
4. Note2: as I have discovered some files were not auto-uploaded, so I have decided to force-upload full library; this is how this issue appeared

Expected behaviour

Library is uploaded to nextcloud

Actual behaviour

1. Nextcloud starts to eat iPhone storage and eventually fails (crashes and cannot relaunch) at using 27+Gb when storage is full. Obviously, there is no need for nextcloud to take up so much space to upload
2. A lot of duplicated files with different names created. E.g. I had one file with all correct metadata placed to year 1980, sometimes years are wrong, sometimes months, days, hours — no idea, why. Sometimes filename date is correct, but there is different random numerical suffix, e.g. "3495" and "39864873246" for duplicates.
3. A lot of zero-size files created

Reasoning or why should it be changed/implemented?

This is one of key features. Essentially, initial upload of a large media library from phone is currently broken. Especially, if you're running out of space.

Environment data

iOS version: e.g. iOS 18.7.1

Nextcloud iOS app version: Nextcloud Matheria for iOS 7.2.3.7

Server operating system:
Debian GNU/Linux 12 (bookworm)
Kernel: Linux 6.12.34+rpt-rpi-2712
Architecture: arm64
I guess this is raspbian, as this is Pi5

Web server: Apache on nextcloud, nginx on my server + cloudflare

Database: pgsql, redis

PHP version: latest

Nextcloud version: Nextcloud Hub 25 Autumn (32.0.4)

No source files or tests are named. Start by reproducing the upload with a large library whose files already exist on the server, then trace the iOS upload flow while monitoring local storage, duplicate names, dates, and zero-byte results. Done means the initial upload avoids unnecessary storage use and does not create duplicate, misdated, or empty files.