I'm no expert - freshly minted PPL, however, flying a 172 I've been taught similar, with the exception that there was no 'ciruit height before downwind' mandate - turn downwind was made when it seemed appropriate.
Normally that started a bit under circuit height, and had me levelling off around the turn completion. Never looked at a GPS trace to see what the numbers are, but with a closer base, your 8 o clock (I'm generally about 45degrees) may need to change - cramping the base too much will make it more difficult to stabilise the final.