I can’t follow whether you’re in Taiwan or the UK.
Anyway, I’m in Taiwan and I get my Taiwanese bank to send TWD to my British bank account. I can’t remember what the charges are, which suggests they are low enough not to be a concern.
Last time I sent some money to my UK account from Taiwan, the fee was around 500NT. Took 5 working days to clear. Almost every bank in Taiwan would be the same I think.
You could buy traveler’s cheques and post them over to the UK (DHL/UPS would probably be better for guaranteed delivery at the moment. But I think you can only get them in US$.
Paypal - you’re only allowed about 1000 pounds I think as a basic user.
Any bank in Taiwan should be able to open a multi-currency account for you. You can then use the app to convert from TWD into GBP at any time you think the exchange rate is good.
Once you have the GBP in your multi-currency account, you can transfer them to your bank in the UK.
In general, transfers are cheaper online as opposed to in-person at the bank, but you will have to go to the bank first to set up the UK account as a designated account, before being able to transfer online.
Depends on how much you’re sending. If small amounts, I’d just do it the easiest way. Send the TWD to your UK bank, and let them handle the exchange.
I used OFX regularly up until a couple of years ago. Pretty good service.
When I looked into it, they gave the best rates. It might be different now, but worth a look.
If you’re exchanging a large amount and don’t like OFX, don’t send TWD to the UK. Change the TWD to GBP in Taiwan, then send the pounds. Do it all online. You will certainly get a better rate this way.