The number 1 ongoing feature request from the community seems to be the wrapping and customisation of the header row. Looks like it’s been around since September 2016 and still not actioned.
Yes. Granular security options; circa 2015. And it’s not how old a request is that matters so much; that is simply a gauge of development pace. Rather, a function like Split() would affect vastly more users and positive outcomes that have plagued the community for almost a decade.