Both Firefox (and its forks like PaleMoon) and Chrome support loading to RAM directly rather than SSD, but disk cache is enabled by default. You can also disable offline disk cache entirely (note: this is not the same as "don't remember my history" option).
Firefox/Waterfox/PaleMoon etc: http://lifehacker.com/5687850/speed-up-firefox-by-moving-your-cache-to-ram-no-ram-disk-required
Chrome: All articles I'm searching state RAMdisk but I know for a fact it can be cached to RAM directly as Firefox et al.
This may help but in my experience my SSD reports 200K+ gB read/write access, under a year even with optimizations. I don't think you're going to accomplish much with trying to "overprovision" as any modern SSD is designed to R/W on all blocks, and Windows especially will find ways to utilize it with or without user optimization. A good SSD should last you a few years light usage, even heavy should be good.
The only reason you want to save yourself the offline writes in /temp storage is to further useable disk space if you have a lesser capacity drive. Offline site data shouldn't even be a thing anyway IMHO, as most webpages do active refreshing every time you load up a site (not the same as in the old days of plain text and graphics which weren't constantly updating).