Powell wrote:

It would not be advisable to use the same phono cartridge
for 33s as 78s. The composition used to make 78s and
the varying grove width will shorted the life of the stylus
greatly.

Thorens offers a replacement stylus for use when playing 78s on its
TD-190 model.

I don't have many 78s and none of them is of any great value, but I
would like to be able to spin them now and then without investing in a
dedicated turntable . . .