Extremely detailed review, very nice but I have one little issue. Did you just say SE864 extends very well in treble region? It stops at 10k or 11k. Does it look great to you?
 
Nevertheless, I enjoyed the review and clicked as helpful. Good job really.

Hi @AmberOzL,  thank you for your kind words.  
 
With my setup regarding the SE846, I feel that it does indeed extend very well in the treble region.  I do not wholeheartedly trust graphs, as there are various intricacies and nuances that cannot currently be recorded with frequency measuring equipment.  Also, using the modded black filters coupled with the SCS elevates every perceived sonic nuance even more than any sizes-fit-all tip.  I have not found measurements of the SE846 with the SCS - even if there were measurements published, they would not be applicable because of the custom properties of the SCS itself - every measurement of every SCS would be slightly different, and would have to be measured using every possible filter and/or modded filter combination.  As a result, I have to go with my heart, and the SE846 (at least with my setup) extends well in every single region.

Very well then, still I would be curious too see how it extends with all those mods and all. If I was you, I would to a quick check the treble with my own ears.
 
http://www.audiocheck.net/audiotests_frequencycheckhigh.php

@AmberOzL, every person's maximum frequency that they can hear will be different, regardless of which C/IEMs or modifications are being used.  For documentation purposes, I checked my maximum frequency that I could perceive regarding the SE846 with the Westone TRUE-Fit, Shure Olives, stock SPC cable, HL Silver Litz cable and SCS  versus the Ref. 1 with clear silicone tips, stock silver/gold cable and TWau cable. 
 
The 'synthetic' results that I observed for both were that I perceived the maximum frequency to be higher with the SE846 (all tips, custom sleeves and cables) than the Ref. 1, regardless of the stock filters or modification I used (I did not use the stock black filters because those are modded [I will not put the foam dampers back in to test]).  Also, the 10kHz - 11kHz measurement, frequency graph, perceived frequency response or otherwise you stated was and is nil, at least to what I have perceived the SE846's highest FR to be with the audio files frequency check hyperlink that you have provided - which I have used before as well as using my own dedicated frequency response emitting application; also perceived as much higher than the 10kHz - 11kHz that was stated.  I will say this: the SCS adds additional perceived frequency response compared to using any of the SE846's sizes-fit-all tips that I used.
 
Again, the tests, be it frequency graphs, perceived frequency responses, a frequency spectrum audio file website, etc. are just that, tests. I am going by my heart, and what I perceived and perceive the FR to be regarding not only the Shure SE846 and Tralucent Audio Reference 1, but every IEM and headphone that I've listed to.  
 
If you want to discuss further regarding my frequency perceptions, frequency tests, etc. please PM me as I do not want this to get off topic. Thanks.