Burning in Subtitles with AviSynth?

[TE16]

I use AviSynth for all my encoding with Simplex264/x265Launcher however there are some of my BD back ups that have English subtitles for foreign dialect that are not hard coded into the original blu-ray meaning it is a separate subtitle stream for the foreign dialect in the remuxed MKV I make.

How can I burn in these subtitles in during encoding with AviSynth and Simple x264/x265 Launcher?

Another question as well, how can I keep the original intended colors and fonts of subtitles? One of my Blu-ray's is The Mummy which has subtitles for foreign dialect that aren't hard coded originally as well as having that particular font for the style of the movie. Is there any way to keep that font when burning them in during encoding?

[sneaker]

1.) extract sup file from Blu-ray
2.) use SupTitle()

For text subtitles like srt/ASS there are similar plugins like vsfilter (incl. forks like xy-vsfilter and vsfiltermod using TextSub()) or AssRender().