Not while using analog input 1. When input is set to analog or SPDIF/AES, the USB output is mixed in just before the D/A converter. If you set Main Input Select to USB, the USB output will go through the grid and global EQ's (like when reamping), but input 1 is muted. You might be able to set input to USB and use input 2 to feed your guitar into the grid via the FX Loop block while the USB input is fed through the input block to a separate row containing an EQ block.
Easier to just use an EQ plugin on the USB return feed in your DAW.