Currently, on desktop when you enable multiselect, you get a nice checkbox in the header of the datatable. I understand why the header gets hidden on mobile, since the grid style changes. But it would ...

just want to say that I cannot fully rely on the type="checkbox", because the space around the checkbox (inside current td) indicated as type="row", but I am sure it should be checkbox too, if you ...

A selected row is typically shown in a DataTable by using a highlight background colour - however, it can also be useful to use other styling options to convey the selected state of items in a table ...