1) if you want to define visible membership as being recognized by the hierarchy, then ok.
2) that would mean that an excommunicated heretic/schismatic is NOT a visible member.
3) we all PRESUME (which is not dogma) that God would remove an excommunication from a repentant sinner, apart from a catholic priest (i.e. hierarchy). We really don't know.
But assuming God would remove such, then that repentant heretic becomes a visible member again, without the hierarchy knowing. Ultimately the term visible/invisible is based on the EXTERIOR knowledge of the Church.
The church does not judge the interior forum, which is why She does not declare that person A died as a heretic and is in hell. She only GENERALLY says that heretics who died unrepentant go to hell.
Also, you shouldn't use the word "justified" apart from the sacrament of baptism. The correct term is, the repentant person died in a state of grace (assuming God forgave them).
The person is not recognized at a member of the Church for he purposes of a funeral (for example). That is what I mean by formal membership. Again, this use of the term is consistent with the way it is used in 1917 Canon Law.
Your second point that I should not use the word "justified" is absolutely false. Here is the chapter from Trent's
Decree on Justification:
https://www.papalencyclicals.net/councils/trent/sixth-session.htmCHAPTER XIV.
On the fallen, and their restoration.
As regards those who, by sin, have fallen from the received grace of Justification, they may be again justified, when, God exciting them, through the sacrament of Penance they shall have attained to the recovery, by the merit of Christ, of the grace lost: for this manner of Justification is of the fallen the reparation: which the holy Fathers have aptly called a second plank after the shipwreck of grace lost. For, on behalf of those who fall into sins after baptism, Christ Jesus instituted the sacrament of Penance, when He said, Receive ye the Holy Ghost, whose sins you shall forgive, they are forgiven them, and whose sins you shall retain, they are retained.
Whence it is to be taught, that the penitence of a Christian, after his fall, is very different from that at (his) baptism; and that therein are included not only a cessation from sins, and a detestation thereof, or, a contrite and humble heart, but also the sacramental confession of the said sins,-at least in desire, and to be made in its season,-and sacerdotal absolution; and likewise satisfaction by fasts, alms, prayers, and the other pious exercises of a spiritual life; not indeed for the eternal punishment,-which is, together with the guilt, remitted, either by the sacrament, or by the desire of the sacrament,-
but for the temporal punishment, which, as the sacred writings teach, is not always wholly remitted, as is done in baptism, to those who, ungrateful to the grace of God which they have received, have grieved the Holy Spirit, and have not feared to violate the temple of God. Concerning which penitence it is written; Be mindful whence thou art fallen; do penance, and do the first works. And again; The sorrow that is according to God worketh penance steadfast unto salvation. And again; Do penance, and bring forth fruits worthy of penance.
So, as you and everyone can see, the term "justification" is used by the Council Fathers precisely in the sense we have been talking about.