If you get back to the UK you can apply there. It will probably be much easier financially
You could apply for yours when/ if approved you could transfer funds to your partner and he could apply. Thereafter you can apply for the dependent visa
The financial requirements time is much easier in the UK. Other countries obviously differ.
The major benefit of the DTV for me is it's for 5 years. I travel often so the multi entry is a massive bonus. Have multiple bank accounts here already while on non o retirement. If over time they close I have accounts in Cambodia that will allow me to scan here. Revolut account allows me to hold Baht and pay anywhere card is accepted which is certainly a lot more than a few years ago.
The absolute benefit is I don't have to visit an immigration office for at least 5 years. That alone is priceless. So for me DTV every time and I'll reassess in 5 years