My wife has just submitted her application for ILR within the UK and Islands. The form is quite similar to the UK application form but not identical. The main differences appear to be: 1] No BRP card required in the IOM 2] A flat fee of £1051 whether posted or hand delivered. They do spend a little time just checking the contents over to see if broadly it is all there. And will give us a call if there is anything missing. They expect to give us a result by text within 2 weeks. 3] They prefer to see the applicant and applicant's spouse in person, so they encourage hand delivery, which we opted for. No kind of premium or same day service available. But would there really be a need? Probably not. The evidence requirements seem broadly the same as for mainland UK. Whilst in the Immigration Dept there was a Pinay submitting her application for Citizenship. She had compiled her ILR in the UK and had since moved to the IOM and was seeking British Citizenship in the IOM
I know how she and yourself may feel, as only recently we received my wife's Permanent residence Card, and stepdaughter's first residence card. I suppose that our journey was a lot easier and definitively cheaper, than what you two had to endure, but the satisfaction of getting there is just as pleasing, none the less. All the best for the future.
I only played the cards that were dealt to me, didn't have to buck anything. The sense of achievement felt by getting the permits is just as satisfying.