Is it a good idea to put detailed supplementary analyses to a publication on ArXiv or Zenodo?
If the journals you want to submit your work are not "ArXiv-compatible" you have few options:

1)Put the excluded material in the appendix of the arxiv submission.
2)Make a write-up, put it on your web-page, and cite it in the arxiv paper.
3)Create a technical report (with a time stamp) and cite it in your article.

I think the time-stamp feature is critical here.