Yes, some peeps autoguide their LX90's that way. However, I'd want to use a autoguider a bit more sensitive than the LPI if I wanted to track objects for long periods. A dedicated autoguider will pick out dimmer stars than the LPI, making it easier to guide with it mainly because of the greater number of guide stars you can choose from. That's why I suggested the #909 clone in an earlier post. But, you can autoguide the scope with the autostar suite and an LPI. If you want to find out off of the experts with LX90's, here's a place to join....
LX90's User Group