Finally made successful cuts with mine today after determining I'm an idiot. Basically, I tried to cut thick rusty steel starting from the middle, blew through all 3 tips in record time and just lightly pitted the surface!
After reading the forum I realised I needed needed pilot arc for what I was attempting so thank you to @zx9 and @Onoff for posting your recent torch adventures as it made ordering and modifying one a breeze (I cheated and just slipped the red wire under the same dinse grub screw as the earth wire for now though).
Cut was slightly better but still not good. I assumed it was my technique and ploughed on until that tip had seen better days. Paused for thought and concluded there wasn't enough air pressure to blow out the molten metal, I considered getting the big compressor out but thought I'd just double-check the rear valve was shut on the machine
My technique could still do with some practice, but made it through this rusty mess eventually. I progressively worked up from about 25A but ended up maxed out 40A for best (fastest/full cut through) results.