The standard Rosetta small molecule docking protocols are typically split into low-res and high-res stages.
If you use the RosettaScripts protocol (e.g. https://www.rosettacommons.org/demos/latest/tutorials/ligand_docking/ligand_docking_tutorial) you can simply disable/remove the “Transform” mover from the XML to disable the low resolution sampling stage. You can also change the settings on the Transform mover to be less agressive about how it samples.
If you’re using PyRosetta, it should be relatively straightforward to translate the XML into a PyRosetta script. Alternatively, I think the D120_Ligand_interface.py does primarily a high resolution refinement. (Though it may be more agressive than the without-Transform mover.)
The flexpepdock protocol (and server) is intended for docking peptides, so it’s not going to work well for non-peptidic small molecules.