Dear Shri Kaustubh Ji,
Let me answer your queries in two parts (First, where circular under discussion is binding on Dept and Second, whether said circular "really" states unequivocally the position which we desire OR we are just trying to interpret it in a way favouring assessee in given situation while ignoring how very same circular can be interpreted differently).
For first part of my answer, same are as follows:
A. While it is true that ''as per Apex Court ruling/s, Circular is binding on the department but not on the assessee", it is also held that circulars are not binding on court.
B. Under CGST Act, 2017, we got specific section to deal with Board's circulars / instructions i.e. Section 168 (1) which states that ''The Board may, if it considers it necessary or expedient so to do for the purpose of uniformity in the implementation of this Act, issue such orders, instructions or directions to the central tax officers as it may deem fit, and thereuponall such officers and all other persons employed in the implementation of this Act shall observe and follow such orders, instructions or directions."
B1. The legal position, as summarised in Para A above, needs to be tested again (i.e. issue is open, which will be eventually settled by Apex Court ... one way or other) when any circular is NOT issued using powers of said Section 168 (1).
C. Another disputable issue (i.e. issue is open, which will be settled by Apex Court ... one way or other) is whether any circular / instruction etc. - which is issued by CBEC using powers of Section 168 (1) and NOT similarly issued by jurisdictional state / UT - will be bidning of officers of such jurisdictional state / UT or not & & vis-a-versa?
In summary, I will be reluctant to 'solely' rely of any any circular / instruction etc. specially if same is not issued using powers u/s 168 (1) OR if same is not issued by BOTH - i.e. CBEC ás well as by jurisdictional state / UT.
And, you will notice that Circular No. 125/44/2019-GST [CBEC-20/16/04/18-GST], dt. 18-11-2019 is not issued using powers of Section 168 (1). So, one needs to be careful there before relying solely on it.
These are ex facie views of mine and the same should not be construed as professional advice / suggestion.