I had a project 2 winters ago with the 12F675 sending commands to an HF transceiver at 19200 with the chips internal oscillator.
I ended up bit-banging the output.
I wouldn't have attempted this if it hadn't been for the fact that the commands were easy to derive.
Basically, commands included: Select next Frequency band UP, Select next Frequency band DOWN, shut off transmit power, turn ON transmit power, scan up frequency, scan down frequency.
The challenge was the commands were 32bit segments.
I used the OSCAL command and a digi-oscope to get the bit-widths correct for that baud rate.
I may have the code stashed away in notes somewhere, but not sure since that was so long ago.
Anyway, just to give a report that the chip can output serial at that speed.
But at that time, I was using PICBASIC (not the picbasic-pro) compiler.
Good luck! and have fun