Drop DVI support
DVI is a very old format that never had any uses outside of TeX community. All modern TeX engines are capable of producing PDF, and not only that:
in modern TeX distributions, latex is pdflatex in dvi mode; the underlying engine is the same
TeX StackExchange mentioned two reasons to prefer DVI over PDF:
you are a heavy PSTricks user
pdflatex's lack of support for eps figures
Support for EPS has been available since 2010:
starting with TeXlive 2010, epstopdf will be called automatically when you run pdflatex, so for all intents and purposes, pdflatex will support .eps
PSTricks website explicitly warns against DVI:
PSTricks is PostScript Tricks, viewing your PS or PDF output with a PS or PDF viewer is appropriate. Nearly all DVI-viewers cannot show rotations or movings, hence not the correct output.
Not only that, but recent versions actually support direct PDF output:
PSTricks (except package pst-text) now works with lualatex, which creates directly a pdf outpunt.
Some files in DVI generator bear copyrights from 1985, e.g TeXFont_PK.cpp.
Code quality scanner has found 9 critical and major issues with the DVI generator. Fixing these issues is difficult for at least two reasons: