This is the interpretation: It is these whom the Most High has kept for the eagle’s end: The Revised Standard Version footnote on the eagle’s is purely translational, so it is not needed. The demonstrative pronoun these refers to the last two little wings, whose identity is unknown. Since they appear at the end of the empire, the author is obviously talking about something future with reference to himself, and they may not correspond to any real people. The first half of this verse may be rendered “These two wings refer to two kings whom God Most High will keep until the end of the eagle’s life.”

This was the reign which was brief and full of tumult, as you have seen: It seems that this sentence is prediction, so the future tense fits better here than the more literal past tense. As you have seen recalls what Ezra saw in 2Esdras 12.2 (see the comments there). This sentence may be translated “Their reign, you will remember, will be short and full of trouble” or “You will remember that they will rule for only a short time and will have great trouble.”

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Esdras. (UBS Helps for Translators). Miami: UBS, 2019. For this and other handbooks for translators see here.