I wouldn't worry about PPS status match, unless you are planning a lot of economy travel in the period you are building status - or want to do a lot of redemptions.

The three main benefits of PPS:
1) Access to the business class lounge whilst flying economy
2) Greetings and first chance of meal selection on board (well behind Solitaire PPS)
3) Preferential clearance of waitlists for award

1) Is not an issue if you are flying so much in business. 2) Is not an issue for all but the BKK-SIN sectors, as you can book the cook for flights out of BNE and SIN to ensure you get your meal choice. 3) You will need to build up points to redeem anyway.

I get that the SIN transit might be an inconvenience, but the flipside is that you get more schedule choice. Also, if you're waiting to get TG 473 out of BKK at midnight, why not take an earlier flight via SIN and probably still get to BNE around the same time or earlier.