FLR (M) for husband who was in limited leave to remain as a parent

[JAKSJ]

Hope someone can shed light on this please. Thank you in advance.
My husband submitted an application for ILR which did not meet the requirements for ILR as there was a 4 months break in the middle of 10 years. Hence HO granted him limited leave to remain under the immigration rules of 30 months as a parent because our child has resided in the IK for 7 years. There was only a confirmation email where there is no mention about what route he is in now. He earned 45k at the time and submitted IELTS for UKVI general score 4.5 and B1 certificate as he had both of them.
This happened in 2021 while I and our son were on FLR (FP) visa. Few months later our son became a British citizen and I was granted ILR on completion of 10 years.
I am registered as a self employed since 2022 and have started earning a profit from July 2023 (approximately monthly £1000). Husband earns 80k currently and have been with the same employer for more than a year and currently work there.
In next month his visa expires and I wonder which application he should fill in. After reading HO information I thought he should fill in FLR (M) application. Does his 30 months already spent as a parent count towards spouse visa and will he be able to apply for ILR at the end of next 30 months as a spouse?
Or else does he need to stay on spouse visa for next 5 years before applying for ILR?
As he used IELTS for UKVI general score and B1 in his visa as a parent in the current visa, can he use it for spouse visa application?
Does his salary alone is enough to the requirements or should I submit accounts for my self employment for the past 9 months together?

Due to a misleading guidance by a previous immigration advisor in a different application in the past, his immigration history was broken in the middle of last 13 years stay in the UK, hence I'm very careful about his application this time.

Thank you very much for reading and your valuable information

[secret.simon]

Does his 30 months already spent as a parent count towards spouse visa

No.

will he be able to apply for ILR at the end of next 30 months as a spouse?

No.

Or else does he need to stay on spouse visa for next 5 years before applying for ILR?

Yes.

As he used IELTS for UKVI general score and B1 in his visa as a parent in the current visa, can he use it for spouse visa application?

Not sure. The parent route and visas on the 10 year route generally don't have a language requirement. So it is possible that the language proofs that he had submitted may have been disregarded. FLR(M) on the other hand has specific language requirements. He'd want to make sure that they are met.

My husband submitted an application for ILR which did not meet the requirements for ILR as there was a 4 months break in the middle of 10 years.

When you say "4 months break", do you mean that he was illegally resident in the UK for four months or that he was absent from the UK for four months?