As I've just booked one of these to replace the Sofia do, just to note there are 200+ TPs available for £282 for a weekend JER->LGW->TIA->LGW starting in November and running up to April with a one night stay - mine is booked on 29th Feb. Note it's open jaw and not a return. After April there are no weekend flights, sadly. Find the relevant days by looking for LHW-JER return on google flights at £243 (also a nice return rate if you don't want the extra 40TPs for £39 the JER start gives you).

Positioning to JER can be done B2B the same day as the TIA flight with a civilised start time, inexpensive in Y and would make it 205 TP for about £330 I guess, maybe less depending on the fare available. There's a 1400 from JER to LGW which gives just over an hour to the TIA outbound at around 1620, if you're lucky it'll be late and you can claim ORC/Trip in vain for Tirana. Otherwise the Hilton Doubletree is cheap as chips for an overnight stay or a 16k HH redemption.

You get quite a lot of Avios back too.

I'm positioning in J using up a couple of PP vouchers doing this, which reduced my overall cost to about £160 for 240 TPs, plus a Hilton redemption. Pleasing.