Not the OP, but I've started putting all my first-author papers in the EarthArXiv [1]. The original ArXiv only accepts preprints from a few fields, but the Open Science Framework has recently made a federation of preprint servers that fills many of the gaps, and can be searched in one place [2].

[1] https://eartharxiv.org/ [2] https://osf.io/preprints/