The difference between a low pressure and high pressure turbo is that the low pressure one is smaller so that it spools up quicker to provide better low end response. The high pressure turbo is larger, takes longer to spool, but provides better top end performance. I don't know if adjusting the wastegate actuator rod will have the same effect on a LPT but imagine it would, to a perhaps a lesser extent than with a HPT. In any event, if your car is still under warranty I would be very careful with any adjustments.