I'm in a similar situation. Was here 4 months late November to March. Spent 3 months back home and then came in again on a 60 day. Done an extension and 1 border run and heading to Malaysia at the end of this 30 days before flying back in. I'm a bit nervous about flying back in but have a flight back to Australia 29 days after I return so I should just cop some questioning hopefully. I miss the good old days when this shit never mattered
So I take it you went 60, 30 day extension, border bounce, extension, border bounce, extension. I'm pretty sure you'll be questioned if you come back in October but you have been in the UK for 3 months so you should be ok but I'm only guessing so. At the end of the day do as they say to do and turn up with the 3 requirements and you'll likely be fine