Too many fonts hurting load speed

Site URL: https://2east8th.com

I'm trying to reduce the number of loaded fonts to 1.  We only use Roboto on the site yet 3 other fonts load as well.  This impacts the page load speed even though they're not in use on the currently displayed page.  Yes I have used Pingdom and it's an issue there too.  Our mobile site load speed is pathetic (9) and many of the items that are listed as highest impact are the "Standard Squarespace Items You Can't Change".  I recently performed an in depth check of all the page types and content types in the template and changed every font to Roboto.  The extra fonts disappeared!  I ran the speed test and suddenly it was a 4x gain!  Hurrah!  Next day I run the test again and we're back down to 10.  I go back to the site styles and now all those fonts I disabled are back again.  Am I doing this wrong or is this yet another thing I can't actually change even though it's having a negative effect on my site?  Has anyone had any luck dealing with this?