I wouldn't recommend filling from zero to 4500 unless you have a Pressure Maintaining Valve (PMV) on your system after your last filter.
Firstly, if you fill from zero, you will quickly expend the media in whatever filters you have in use as you go through the first thousand psi.
Secondly, running your compressor for that amount of time, although the manufacturer says its OK, will "wear" your first and second stage rings very quickly.
The smart thing to do when you get a new SCBA tank is to take it to a dive shot to get it filled. If the tank is expired, and you can't do that, top off the largest tank that you currently own, and then hook it up to your new tank and equalize pressures. You should be around 2000 psi give or take. Then fill both with your compressor, and you get around the "not having a PMV" situation...
Just my two cents based on previous experience with the two cylinder Tuxing which is basically the same compressor as the Hatsan and AV.
Mike