Must admit having been brought watching traditional navigators baby sitting the early inertial systems to get a working alignment and done a bit of the same on a classic airframe the “I’d aligned it up for you, why have you recycled it?” comment is one of my pet peeves.....(though I know people are well meaning and have their reasons...)
I can’t talk for the 787 but on traditional types there is/was often a maximum time limitation between full inertial system aligns (to prevent accrual of errors) and also a requirement for the operating crew, not the engineer, to enter/ensure the correct PPos is entered at the start of the alignment process.....
AFAIK the only way crew could ensure both of the above was to turn the system off and on again as part of the shutdown and/or preflight procedure....which is possibly whilst it might still be in a checklist.. Whether there really is any reason these days for such precautions I don’t know....and yes, nowadays there’s the added issue of loss of satcom whilst the system is off or aligning....
Ultimately you follow the checklist...but yes I am old fashioned.....