SINGER isn't coping with .vcf.gz file

I have been running parallel singer recently. Most other programs will happily take a .vcf.gz file (i.e. gzipped vcf) to save space. However, this format doesn't seem to be working in SINGER at the moment. 

Are their plans to fix this/ am I missing something? There is, of course, a substantial difference in storage space between gzipped and non-gzipped vcf files. 

Regards. 