By going through the glyph set, the font supports only the contextual forms, consonant clusters etc. which are mentioned in the Unicode proposal. No other sources ( primary sources like manuscripts, primers etc.) seem to consulted/researched. Thus the font is unusable like most other complex historic and minority Indic scripts' Noto fonts. page 5 of the Unicode proposal L2/11-175R mentions some contextual/special forms for vowel sign UU, but they are just examples not the only forms.
Observed form:
Correct form from Tirhuta primers.
Character data
𑒞𑒴
U+1149E TIRHUTA LETTER TA
U+114B4 TIRHUTA VOWEL SIGN UU
Title
'NotoSansTirhuta-Regular.ttf.
Where the font came from, and when
Font Version
Issue
Character data