Error in search for in Bibles with Reverse Interlinears

Lee Patmore said:

How many other places does the SBLGNT not include a word or a phrase that is in the UBS4 or the NA28?

That should be documented in the Apparatus:

There's also a table summarising the differences between GNT editions in the Introduction.

Lee Patmore said:

Why are the reverse interlinear bibles not based on the Greek text that actually stands behind them?

I'm not an expert on this, but my understanding is that those Greek texts aren't actually available. Each translation ends up being based on its own eclectic Greek text as the translation committee chooses different readings during the translation process, and only the major differences tend to be documented in translators' footnotes. (Sometimes the underlying Greek text is made available, as with Goodrich & Lukaszewski's A Reader's Greek New Testament, or Scrivener's GNT, but I believe both of those were "reverse engineered" back from the English translation, and not a product of the translation committee.)

We do not have the budget (or omniscience) to reconstruct each conjectural underlying Greek text from the English (or Spanish, German, etc.) translation as part of the reverse interlinear alignment process, so for simplicity we align everything to either the SBLGNT or TR based on the manuscript tradition the translation uses. This is just something to be aware of when performing Greek studies on a reverse interlinear: for the most part, you're studying the SBLGNT.