On the 1st of June, 1830 a small meeting was held by about thirty people who comprised the church. The meeting was in a home. During the meeting Newel Knight was carried away in a vision. Only Brother Knight had the vision, but Joseph accepted it as true and had it put into the history.
Here is what Newel Knight's visionary experience included:
"He saw heaven opened and beheld the Lord Jesus Christ, sitting [at] the right hand of the Majesty on high, and had it made plain to his understanding that the time would come when he should be admitted into his presence to enjoy his society for ever and ever." (JS Papers: Histories Vol. 1, p. 388, Draft 1; punctuation and insertions as in original.)
That example shows how open Joseph Smith was to allowing others to both receive revelations and for their revelations to be regarded as authentic and trustworthy. Joseph trusted in this visionary experience of Brother Newel Knight so much it was included in Joseph's history.
This experience would be described as Brother Knight's calling and election being made sure, since it includes the promise from God that he (Bro. Knight) will be able to enjoy Christ and the Father's "society for ever and ever."
It is not regarded as "too sacred" to discuss.
It is not regarded as impudent to have a visionary experience apart from Joseph.
It did not excite Joseph's jealousy or condemnation, but inspired his confidence and faith.
It happened in a home, although it was a church meeting. No church buildings existed among the Saints during Joseph's lifetime, other than the Kirtland Temple. The people met in homes or outside during Joseph's lifetime.