They need to own and fix the two Q4 labels but as far as parts values, the schematic is correct. Also a small part of me imagines some future idiot posting on a troubleshooting thread about the pedal not working because of the two Q4 issue.
28K + 4n7 and your corner frequency will increase about 4 Hz. Probably your best bet for a sub - he said before considering common resistor values. sub 3n9 and keep the 33K, corner increases 31Hz