HSP not displaying .webp thumbnails

SLR recently changed all of their cover/gallery files to .webp default; now any SLR scenes scraped fail to display cover thumbnails in Heresphere. 

Is there a way to configure the XBVR imageproxy to convert all covers to .jpg? Or for the SLR scraper to grab the .jpg versions (simply changing the file extension on the URL seems to work) instead?