How to create a multi-part archive from a folder?

I have a large folder (1.8 million files, 40 GB on disk) that I want to archive for easy transfer. I can zip the folder using ditto like so:

ditto -c -k --sequesterRsrc --keepParent 2-experiment-logs 2-experiment-logs.zip

And I cannot split the archive using zip like so:

zip 2-experiment-logs.zip --out 2-experiments-logs-split.zip -s 1024m

Because I get an error like so:

zip warning: unexpected signature on disk 0 at 551121334

	zip warning: archive not in correct format: 2-experiment-logs.zip
	zip warning: (try -F to attempt recovery)

zip error: Zip file structure invalid (2-experiment-logs.zip)

How to fix this issue? Is there a way to create a split archive directly, without creating the monolithic archive as an intermediate step? https://ss64.com/mac/ditto.html