No battery level and motor assist

[Cargo_Bike_Bristol]

do you mean cheaper than the Bafang BBSes? Nothing is much cheaper. The Tongsheng bb motors have torque sensor and cost about 5% less than their Bafang competitors. However, the Bafang have bigger motor compared to the Tongsheng. Tongsheng has just brought out their TSDZ2B Turbo with the same motor size and weight and costs the same as the Bafang.
If you like torque sensor, wait for the 48V TSDZ2B turbo, otherwise buy 48V Bafang.
The main issue with using bottom bracket motors for a cargo bike is chain wear. They eat through chains because of the heavy load you carry. Hub motors like the DWG22C don't wear chains.

Yeah I meant those, to be honest it sounds like the Bafang mid drive is the one to go for as the hill we live on is so steep and busy so standing starts is not uncommon and the kids are only getting heavier. Cheers for the guidance, I'm feeling good about having a way forward now as I haven't touched the bike since last year as I got so fed up with it. I'm fine with replacing chains to be honest, beats opening a second car eh!