One thing Medivisas did say was that I can apply on the basis of my new employment as soon as I have earned £18,600 from this job, even if that comes before the 6 month mark. I am skeptical of this advice though as the guidance seems to be very clear on the UK.gov webpage. I forwarded this suggestion to a 2nd immigration lawyer and he agreed it is fine for me to apply as soon as I hit £18,600 gross. I will reach that milestone in January, about 2.5 months after starting the job, so this makes for a very appealing option but I am desperately seeking some assurances here that some of you have seen others take this route and that it is indeed possible? I am also bemused as to why none of the other 5 lawyers I contacted offered this as a solution.
From what I can tell, I think this advice is correct, because it would mean you could meet the requirements under Category B, for which you must meet the following 2 requirements:
1) You earn a salary of more than £18,600 per year but have been with your current UK employer for LESS THAN 6 months
and
2) You have earned at least £18,600 in the last 12 months from any job(s), in the UK or overseas.
So, if you can show you have earned at least £18,600 in the last 12 months, NOT including your US self-employment income (i.e. you have earned £18,600 or more just from your new UK job), then I believe you can apply under Category B.
Edited to add: I don't think I've seen anyone else actually apply this way though... but that's because almost no one on this forum has secured a job which pays enough that they can earn £18,600 in less than 6 months
. In many cases, the sponsor's job only pays a little over £18,600, so they would qualify under Category A before they earned £18,600 total.