A break in a transcribed historical text can make a sentence tantalising. Before imagining the missing words, identify what kind of absence the edition records.
Read the editorial explanation
The TEI guidance for gap distinguishes reasons material may be omitted from a transcription, including editorial selection and inability to read it. A visible gap therefore does not automatically mean that the physical manuscript has a hole of the same size.
Keep reconstruction on another line
Write what survives, what the edition says is missing and any proposed restoration separately. An attractive completion is still a proposal unless supported by evidence. Do not silently insert it into a quotation as though it were preserved wording.
For a reading exercise, compare how two editions explain the same interruption. They may follow different policies rather than possess different physical evidence. This distinction lets you discuss an incomplete argument without filling every space with the sentence you expected the ancient author to write.