I believe incense is required for a Stational Mass of the Diocesan Bishop.
This is described in the Ceremonial of Bishops (the Latin edition, Caeremoniale Episcoporum, was published in 1984):
STATIONAL MASS OF THE DIOCESAN BISHOP
119 The preeminent manifestation of the local Church is present when the bishop, as high priest of his flock, celebrates the eucharist and particularly when he celebrates in the cathedral, surrounded by his college of presbyters and by his ministers, and with the full, active participation of all God’s holy people.
This Mass, which is called the stational Mass, shows forth the unity of the local Church as well as the diversity of ministries exercised around the bishop and the holy eucharist.[Footnote 1 See Sacronsanctum Conciliium, n. 41]
Hence as many of the faithful as possible should come together for a stational Mass, priests should concelebrate with the bishop, deacons should assist in the celebration, and acolytes and readers should carry out their minstries. [See Sacronsanctum Concilium, nn. 26-28]
120 The form of the stational Mass should be retained especially on the greater solemnities of the liturgical year, on Holy Thursday for the blessing of the chrism and the Mass of the Lord’s Supper, [footnote 3, see GIRM, nos. 157-158] at the celebration honoring the founder of the local Church or the patron of the diocese, on the anniversay of the bishop’s episcopal ordination, at large gatherings of the Christian people, and during pastoral visitations.”
It writes about the use of incense as compulsory. It is not a case of “if incense is used” as in the General Instruction of the Roman Missal. Rather it has, for example, :
“128 As the entrance song is being sung, the procession moves from the vesting room (sacristy) to the sanctuary (chancel) in the following order:
– censerbearer carrying a censer with burning incense;”
From the 2002 General Introduction to the Roman Missal (GIRM) approved for the USA, which can be accessed from romanrite.com/girm.html :
"276 … Incense may be used if desired in any form of Mass: ". This sounds like it is always optional. But it also has in the 2002 GIRM:
“112 … At a Mass celebrated by the Bishop or at which he presides without celebrating the Eucharist, the norms found in the Caeremoniale Episcoporum should be observed. [footnote 92: 92. Cf. Caeremoniale Episcoporum, editio typica, 1984, nos. 119-186.]”
I would not expect the bishop to cancel Mass on Holy Thursday because they have run out of incense. But to faithfully follow the litugical books it should be used.
Reference: Ceremonial of Bishops, Liturgical Press, 1989, ISBN 0-8146-1818-9.