After reading many threads on multi O visa I am still somewhat perplexed

My 12 Month multi entry O visa will expire by September and with a further 90 day stamp
bringing up to Dec 4 will be a requirement to renew I understand there is the
option of extension via retirement with 800,000 ect also I am now married to a Thai and aware of
the 400,000 copies of this and that

I note that Savannakhet is a good option for many at “this time”

My Two questions:
Do I have to go to somewhere like Savannakhet or KL to get my first Marriage
visa or my local immigration office Phuket

2: Do I have an option of another 12 month multi O
Where could I apply? I am a UK citizen with my last visa issued in Birmingham

Thanks in Anticipation

There is no marriage visa - the non immigrant O visa is "other" and applies to marriage, volunteer work, retirement and such so what you have it what you would get. If you extend a current stay using Thai wife as the reason you will need the 400k/40k requirement and do at immigration where you live. If you want to stay on 90 day visa entries the best choice would be a visit to Savannakhet to obtain another multi entry non immigrant O visa or KL if you meet there requirements (but check closer to time for any place as they can change).

Your input has been very help full Thank you