I would much rather if Proclaim didn't change my text to add ligatures. Is that intentional, or is it a bug?
Has it changed the unicode? If so, I'd object as well. or is it simply the kerning routine for the font causing the type to run together?
What font are you using?
The screenshot is from Lato.
Yes, I believe it's replacing the letters 'f' and 'i' with a single unicode character.
I tried almost all of our fonts and many of them display that ligature, including Lato, there are many that don't though.
Lato is a public font available under the Open Font License and I do not think this is a bug with Proclaim or the font. The work around is to use a different font.