Will airport screeners allow an inkjet printer, if removed from my carry-on and placed on an Airport Security Tray?

Though this answer is for an OfficeJet 8710 that’s too big to fit inside a carry-on, it warns:

But more importantly, there was a bomb threat a few years ago that involved toner cartridges and thus the TSA has treated them in the past like potential bombs. While the ban is officially lifted, it just takes one zealous TSA officer to make a mess of your printer. Not advised.

My grandparents are now contemplating packing a smaller OfficeJet 3830 in their carry-on, without ink cartridges.

  1. They can happily remove the printer from their carry-on and place it on an Airport Security Tray. Is this necessary though? Is it sufficient simply to notify the airport screener that their carry-on contains an inkjet printer?

  2. Will they face any difficulties with airport screeners?