I have a couple of small research projects that I have recently made some progress on and gotten (I think) useful preliminary results. It is not enough for a peer-reviewed paper yet but I anticipate it will at some point in the future. At the moment, I need to focus on other work to make progress on my main projects.
My question is this: Suppose I want to put out some preliminary work that people in my field may find useful. Would posting a preliminary paper on an official preprint server that issues a DOI (i.e. engrXiv, Preprints, etc. - arXiv does not accept papers in my area) or writing a technical report be more useful? There is no guarantee I will have time to return to these projects in the near future. I want others to read the work freely and widely but I also want to protect any intellectual property here so I cannot just post the work on a random website - there needs to be some "official" status that other people may be able to build upon.
For technical reports, my university publishes formal technical reports in the College of Engineering library repository. Either way (preprint or tech report), the work will be indexed in Google Scholar and be citable. In my field, formal technical reports count as minor publications (equivalent to conference papers) and preprints may set the expectation that a paper is complete and in-review.
Advice and discussion of the pros and cons of both approaches would be appreciated.