Don't extrude faster than 5.6 mm^3/s with any filament in compound extruder to start. Get success first with no skipping then try to push the limits. Do the math: 45mm/s movement, 0.3 mm layers and 0.5 mm wide would be 6.75mm^3/s , a bit to fast for your first print, especially with pla. So adjust layer heights accordingly, for example to 0.25mm high for your first prints. Over time you should be able to print faster. Remember that speed depends on material, number of print moves per second, nozzle type and temperature.