What is the best way for a Canadian to obtain a Thai O-A Visa for a 7-month stay?

I am a 58 year old Canadian citizen looking to spend 7 months in Thailand and am looking evaluating the O-A Visa for 1 year. I am 58 and have the financial requirements but am at the start of the process to fill out the forms which seem to have to be notarized and signed by the Consulate General. I have 5 months to obtains this O-A Visa as I want to stay for 7 months this year (end of Oct 2025-April 2026). Any advice regarding the scheduling of duties? police report, proof of funds, proof of Health, Insurance. It seems the only alternative is Multiple- Entry-Visa (which 1. Includes the cost and disruption of Visa runs and 2. Officially states the ‘up to 6 months and I need almost 7 months) I know Thailand fairly well and have a good contact there who lives in a retirement visa from Europe but on prior trips have spent just 4 months at a time. Ultimately the O-A retirement visa is what I think is my only choice as I negotiate a longer term visa commitment. Also I have noted that some people are having difficulties with the Multiple Entry route in terms of re-entering Thailand and encountering different requirements from different immigration officers. I’m curious if anyone else has successfully obtained this visa recently and if so, how long it might have taken as well as details or advice on issues encountered during the application process. Any and all advice would be much appreciated.