RE: exporting to Excel from SmartList
If you have a SmartList report that will return 50,000 to 100,000 records without an error or crashing GP, you're doing good, as usually we see issues when we get as many as 5000 to 10,000 records or more with SmartList, as it isn't actually designed for a large volume of records returned, more of a quick query view. We usually recommend using Excel Reports and/or SSRS reports for larger volume of data.
That being said, even with the enhanced switch, mine appear to be using XLSX, but again, I don't know if the file extension is what would cause GP to crash, more that it is an issue that SmartList really isn't designed to return 100,000 records. I'm surprised you're able to export 50,000 without any issues, to be honest.
Thanks