There is no “Marker [5]” mentioned in the drops to my knowledge.
Only “Marker [1] (505, 3231, and 3232 as a repost), Marker [2] (3232), and Marker [9] (3717 & 3716) specifically are written.
3092 has “[Marker 1 Complete]”.
1464 has “1:07 [Marker]”.
There are 33 posts with the word “marker”.
Interestingly, back to bitts musings) Drop 704 and 704 together may support e=5 vector. hypotheses.
704
[e]
705
[5]
e5 is also a chess move and makes me remember the reference to the famous game - might be time to look up all the moves and see how each listed move compares to the timeline .... would tell us what the final move is as well.