The circuit needs to be flown at 1000ft.
No, you need to look at the "AIP" (Aeronautical Information Publication) or the "A/FD" (Airfield/Facility Directory - a US thing) for the circuit height for the airfield involved. It can be anywhere between 700' and 1500'. And that's above aerodrome level (AAL) - it may be something completely different on the QNH ("altimeter setting" in MSFS).
decreasing to 600ft at the base/final turn (at say 1/2 mile out.) Do you watch the PAPIs on Final? They are at the 3deg glide-slope.
A three degree slope (the normal PAPI/ILS slope) is 2000 feet in 6 nm (6.2 to be precise). So at 1/2 nm out you should be at about 160 feet, and not at 600 feet.
In a light aircraft you can descend a lot steeper than the standard three degrees slope though, so 250-300 feet at 1/2 nm out is still doable, although you will have four whites on the PAPI at that stage.
600 feet at 1/2 nm? I'm pretty sure someone will come out of the woodwork claiming that they can do it with full flaps and full sideslip but if you're landing on a short runway it is probably prudent to start the go-around.
Heck, if you unintentionally end up in that position, you've probably done so much wrong already leading up to that moment that it's best to fly away from the circuit, orbit in a quiet spot for a while to gather your wits and think about what you've done, and then try again. (Or hit the P button in MSFS.)