Rclone copy large files to the cloud yandex.disk

Trying to copy a folder from my laptop to the cloud Yandex.disk with the command
.\rclone.exe copy d:_Doc_home_1\ remote:/BackUp_kg_notebok/_Doc_home_1 --size-only --progress --transfers=30 --buffer-size=500Mb

I'm trying to use it.
The 400Mb data is copied as follows.
Initially, in 10 seconds, all small files of the order of 100 MB are copied through many threads.
Then the single largest file of 300MB size is copied slowly and for a very long time approximately 30 minutes.
When copying one large file, one thread is used.

If you look at how the program works yandex.disk 3.0

It uses about 20 to 30 threads throughout the upload.
It probably knows how large files in multiple threads to throw.
Can Rclone is able to send one file through many threads?
Tell me how to fix my command so that large files are quickly copied to the cloud.
I would be grateful for any advice.

rclone can do it but not with the yandex backend at the moment.

The public API doesn't mention a multipart upload API

https://tech.yandex.com/disk/api/reference/upload-docpage/

What api does the yandex.disk use?

I tried to upload a large 7GB file to yandex.disk using the native program yandex.disk 3.0
At this time, I followed the connections of the program yandex.disk 3.0 via SysinternalsSuite\procexp.exe
Sometimes single connections appeared briefly.
After about 60 seconds, the program Yandex.disk 3.0 told me about the successful upload of the file to the cloud.
I checked, the file in the cloud really appeared.
We can conclude that yandex cloud saves itself in the database all the files that have ever seen.
And before, how to upload large files to the cloud native program checks the presence of this file in the database.
If this file is in the database-the file with high speed is uploaded to the personal cloud.
Is it possible to set some key for Rclone, so that when uploading files through it, this described effect also works?

The new (in the latest beta) mail.ru backend does this.

I don't think there is a public API for this in Yandex disk unfortunately. (Actually I think the mail.ru API was reverse engineered).