Thought I'd put out a slightly left-field suggestion here. There are some half-decent double TP runs available with the cheap WT+ fares under the sale. KUL is already a reasonable price, but other cities in Malaysia with a connection at KUL are in fact cheaper, such as Johor Bahru (near Singapore) and Penang. Start in JER to avoid the APD and you can book something like the following:

JER-LHR-KUL-PEN with an MH connection KUL-PEN (unfortunately no BA codeshare available for the last leg, but it's only short-haul economy so doesn't make much difference to the TPs earned)
5 nights in Penang in a 4* hotel
PEN-KUL-LHR-MAN

At a cost of £1018 (inc. hotels) for 520 TPs = £1.96 per TP, based on dates over one of the May BHs next year. Plenty of availability from November onwards - check the calendar view here on Google Flights.

Of course if you go for car hire then it can be even cheaper.

Obviously it does involve two long overnights in WT+ which isn't the most comfortable prospect, but for the distance it's still a decent fare. Always the chance of being able to upgrade to Business with Avios or of an op-up on the day because of WT+ being a small (and often overbooked) cabin.

Assuming you are a Gold member and have a BAPP Amex, you'd earn about 24k worth of Avios (≈£240) based on the flight earnings, BA Holidays bonus and from the Amex, so the effective cost is reduced to about £775, which isn't bad at all.