Mortgage holiday on maternity leave

Hurstsupply

We have a mortgage with a decent rate of interest which we actually got when I was on maternity leave. No issues with me having reduced salary at the time.
However this maternity leave I plan on sharing with my husband who now earns more than me. So he will be without a salary for 3 months.

While we can just afford the mortgage even on my salary things would be more comfortable and relaxed if we could take a mortgage holiday. (The alternative is to sell some shares which are fairly stagnant at the moment)

My question is around
1. How to calculate the additional cost we will have in taking 3 months off
2. How to ensure it doesn't negatively affect our credit scores.

Also welcome to give opinions if a mortgage holiday is good idea or not.

BoGoF

Was a thread here recently where a payment holiday was showing as an arrangement to pay on credit file.

Personally, unless in financial hardship I would continue paying the mortgage.

And I believe some lenders don't do payment holidays.