Japanese conversion sokuon romanization etc

[lichenophile]

I noticed sokuon translates fine in modes other than furigana (similarly with yo-on)

Is this issue caused by some limitation of the furigana mode, or can it be solved?

I suppose it'd be neat if katakana choonpu/ー romanized into the appropriate vowel too!

Furigana mode:

• the small tsu/ッ should render the furigana as an extra t instead of tsu (dictated by the following kana/mora)
• ー should render as an extra u (in the case of ル) or modify the preceding ru romanisation into rū

Normal mode (correctly displayed):