My apologies - I was using pspg incorrectly. If it's called via the pipe then all the column wrapping is ignored, and that's why I couldn't reproduce the issues. If instead pspg is used via "\setenv PAGER pspg", then I indeed can't scroll the table horizontally more than 1 character, and that's definitely broken.
I'll be using "\pset format wrapped" from now on, it's good enough. My only issue would be with copying the long cell contents, but that's an uncommon case and can be worked around without too much trouble.
pspg supports copy cell to clipboard - you can copy complete cell, although some parts are invisible
