It is not recommended to modify any products; this may cause the product to no work properly and will also void the warranty.
The Ladera Towel Bar #BTB-LR2C protrudes 3 7/32" from the finished wall to the front of the bar. Below is a link to the specifications of this model for further details. https://pfisterstorage.blob.core.windows.net/documents/ss-btb-lrx.pdf
No, I don't think so.