Sexual maturity differs for lots of plecs, for zebras it can be about 3+ years, but to get F1 bristlenose it can take as little as around a year. However it is not easy to track down adult or at least sub-adult bristlenose of a variety of species, then you can just get right to it...
For example the albino bristlenose can attain sizes of 1.25-1.5 inches in 2-4 months, so you'd have a bit of a wait. 1" is pretty small, you would have a while to wait with many of the species.