When do u spend ur reward UTXO & why?

[Shymaa-Arafat]

May I ask u as a miner community, when do u usually spend ur UTXO reward? and why?
.
-I heard in a paper presentation that miners have to wait maybe 100 blocks before spending their rewards.
-However, when I observed the block stream I found 100 blocks is like a min no, with av of order 10⁵ blocks?
-So I came to ask u as miners about the true values; the strict min no of blocks u r forced to wait, and the average no u normally do.

-I'm asking as a part of analyzing the lifetime of different kinds of UTXOs in building the Merkle Tree (if u wonder why I'm asking)