Mini Thermal Printer doesn't accept printing parameter commands

My ‘mini thermal printer’ doesn’t seem to accept the ‘Control Parameter Commands’ described in section 5.2.9 of the manual on the product page.

Specifically, the sequences ‘ESC 7 n1 n2 n3’ and ‘DC2 # n’ do not have the expected effect (changing the print speed/density), and the printer prints out ASCII characters corresponding to whatever values I used for n1, n2, n3 etc.

Are pimoroni able to provide a reference for the command set actually supported by this printer?

The firmware version printed by the self-test is “GV2.16.08 20180627_R”.

Same for me, see my Post for a picture.