For some reason I tricked myself into thinking options(repr.matrix.max.cols=Inf) didn't work, and I tried options(repr.matrix.max.cols=.Machine$integer.max) instead, this causes the following error when showing any object:

# Warning message in cols + 1L:
# “NAs produced by integer overflow”
# ERROR while rich displaying an object: Error in rep("---", out_cols): invalid 'times' argument

Probably we should just interpret .Machine$integer.max to be Inf and be done with it :)