Mix of Class 1 and Class 2 in the same tax year

Please can someone explain if I am overpaying (voluntary) Class 2 by paying the full 52 week rate? I have part time employment during each year on an intermittent basis, so whilst some Class 1 is deducted for those months when I do work, it is below the annualised LEL and so does not, of itself, give me a "full" year. I also undertake intermittent self employment which totals less that the small profits threshold, so I am not "credited" with a Class 2 contribution, and have therefore being voluntarily paying Class 2 using the full 52 week amount, Questions: a) can I pay less than 52 weeks Class 2 on the basis that some NI has already been paid under Class 1? b) if yes, then do I reduce my Class 2 calculation on the basis of the Class 4 total divided by the Class 2 weekly amount = number of weeks I can exclude from the voluntary payment? As an example, for 23/24 my record says: Class 1 paid employment £355.03 and SE 52 weeks. So have I "overpaid" NI in that year? I am not concerned about qualifying for contributions based benefits, so the Class 1 is of no "use" to me as I am only concerned about securing the "full" year for state pension purposes.

Hi,
You may be due a refund of voluntary Class 2 National Insurance contributions (NICs), we would advise you to complete form CA8480 which you can find here:
Apply for a refund of Class 2 National Insurance contributions (CA8480)
You can also ask on the form CA8480 for advice paying voluntary Class 2 NICs going forward. Unfortunately, it is not possible to give concrete advice on how to pay voluntary Class 2 NICs without access to your National Insurance account.
Thank you.