Most people like to say TS Ichigo isnt transcendent because he is sensed by rukia and some mid-level sternritters, but the thing is, transcendent beings can deliberately lower their reaitsu, Aizen does this and explains it:

[https://imgur.com/a/Dwz2GUG](https://imgur.com/a/Dwz2GUG)

I think Ichigo was also lowering his reaitsu, the reason is cause even though they can feel his reiatsu the cant fully grasp it (similar to how tatsuki could feel Aizen's reaitsu but not fully grasp it),

the only person who can fully grap TS Ichigo's reaitsu is SK Yhwach, Orohime is literally next to Ichigo yet can't see the reaitsu taking shape:

[https://imgur.com/a/rMgl106](https://imgur.com/a/rMgl106)

this is why I believe he was lowering his reaitsu

another point is that the only people who can sense SK Yhwach's reaitsu are TYBW Aizen and TS Ichigo (second picture)

as we know only someone who is transcendent can sense another, and since we know Yhwach wasnt lowering it and as a transcendent being was the only one who can fully sense Ichigo,

again just a hypothesis that should be taken into account, cos we know he was massively holding back and only took it serious vs Yhwach (cour 3 and cour 4)

TLDR: I think TS Ichigo is a transcendent being, who was lowering his reaitsu

Arguement for transcendent TS Ichigo