Beginning FLR(M) application before wedding

Hi everyone, would very much appreciate opinions/experience on this.

I'm currently on a Tier 2 Visa, set to expire in March 2021.
My company is closing our office here and moving my role to London. They've offered me redundancy or the option to move.

Myself and my partner would like to stay where we are. We've been together for 2 years and living together for half that time. We have decided to get married and apply for a partner visa so that we can continue our lives here.

We've given notice and are having the ceremony in the beginning of April. I've spoken to other people and have been told getting an appointment for the fast track service can take ages. This has me a bit worried as my company would like a timeline for when I can accept redundancy.

My question is can I begin the application process before we are married? Pay the surcharge and begin filling out the paper work etc? and possibly start trying to book an appointment?

Any help you can provide would be much appreciated!

I've spoken to other people and have been told getting an appointment for the fast track service can take ages.

No it doesn't. The old premium service centre system yes, not the new UKCVAS system. Also note that the date of application of a spouse visa is the date you submit and pay online, so make sure this is not before you are married.

My question is can I begin the application process before we are married? Pay the surcharge and begin filling out the paper work etc? and possibly start trying to book an appointment?

Yes, but you cannot submit the online form until you are married. It is not difficult to get appointments as stated.

Thank you that's super helpful to know!