First of all, forget about the simulator. It's a piece of junk. If you really want, there are modified versions of the simulator that support HD (the stock one does not), but they still don't track the behavior of a real TiVo closely enough.
Second, I don't know how many people use 1.4.1e. It's broken in a number of ways. And you don't actually need it to do HD.
Second, I don't know how many people use 1.4.1e. It's broken in a number of ways. And you don't actually need it to do HD.