But I am thinking there must be some serious airport problems if two arrivals, one in the morning and one in the evening cause so much of a problem. Total of 80 seconds per day lost due to runway exit at the end. Non if the other runway is in use.
From Deloitte:
Deloitte has calculated that in Europe the most valuable landing slots are those at London Heathrow, followed by Charles de Gaulle, Gatwick and Frankfurt. Based on a recent transaction the implied value of a pair of peak time slots at London Heathrow is currently worth between £25 and £30 million. The value of slots varies primarily depending on the time of day they are for.
80 seconds is an extremely expensive amount of time, perhaps not quite a pair of slots but definitely one half of a pair. I've had similar reports about A380 brake cooling times but I think a 3600m is excessive. 2000m should be achievable but considering the issues perhaps you could compromise with them on 2700m. Take control, both on the RTF and by engaging the airline with your issues.