I am not sure why the Ramban [M. ben Nahman] [not the Rambam] is ignored when it comes to the question of entering into the area of the Temple [in Yerushalaim]. His opinion is stated in tracate Avoda Zara 52b.
It comes up concerning the subject of holiness of body קדושת הגוף. That is there are things like a sacrifice that can not become חולין secular. There are other things that become secular if one puts money in their place. An example is if one puts aside his lot or some object for the use of the Temple. That can go out to be secular if one put money in its place. The question over there is the altar. It is there that the Ramban states his opinion that the Temple itself went out to be secular.
[Thus the people that go up to the Temple Mount at least have the Ramban to depend on. I vaguely recall the Raavad has a similar opinion.]
[Years ago I was definitely aware of the Raavad but not the Ramban.]
In terms of law I generally think it is OK to depend on any opinion in the rishonim.
It comes up concerning the subject of holiness of body קדושת הגוף. That is there are things like a sacrifice that can not become חולין secular. There are other things that become secular if one puts money in their place. An example is if one puts aside his lot or some object for the use of the Temple. That can go out to be secular if one put money in its place. The question over there is the altar. It is there that the Ramban states his opinion that the Temple itself went out to be secular.
[Thus the people that go up to the Temple Mount at least have the Ramban to depend on. I vaguely recall the Raavad has a similar opinion.]
[Years ago I was definitely aware of the Raavad but not the Ramban.]
In terms of law I generally think it is OK to depend on any opinion in the rishonim.