Home office

Hello guys, in regards to a friend of mine. If you are a non EU citizen, though FULLY SETTLED ILR holder, do you need your expired passport together with your new one, as she initially arrived here on a marriage visa , so the vignette(currently expired) is in her old passport. Would her residence permit card(confirming pre-settled status) which is still valid and she received it prior to her fully settlement status be enough together with her valid non-EU passport or should I post her expired passport where she is before her return to the Uk? Also would it be neccessary even if if the vignette is expired or would her current passport be enough at the Uk border on her return as her details are electronically registered. Pass control has a sophisticated system, Does she really need a print out of her immigration status or are these suggestions about “holding a print out etc etc” scare scenario written by panic-minded people? Thankyou