In my version of TAGSETS.EXCELXP, when I use the doc='Help' suboption, I don't see any window sizing options.
ods tagsets.excelxp file='print.xls' style=sasweb
However, when i use Office 2007, I do note this behavior: when I maximize my Excel window and then close Excel while in maximized view, the next time I open a spreadsheet, it opens Excel with the last-used settings -- in maximized view. And, if I resize the Excel window to be really tiny before I close Excel -- then -THAT- is the size (tiny) used the next time I open Excel. If there is an XML setting for display size, I don't see it.