1 year for BC application submit

Hi,
While applying naturalisation and then british passport, queries are:

1. In my ILR and foreign passport, surname has space between two words for ex: poli setty whereas my actual surname was polisetty. Can I write surname 'polisetty' as single word without spaces?. As there is no change in letters and generally surname will be single word, does Homeoffice / HMPO accept this?

2. From date of applying naturalisation, my foreign passport going to expire in 5 weeks. Hopefully, by the time of applying british passport, I may have to submit expired foreign passport along with UK ILR card.
Does passport expiry during naturalisation process lead to any problems?

Please help and advise. Thank you

Thanks
PS

Name should by the same as in your passport on and BRP.

Hi,
After ILR, 1 year has to wait to submit BC application. If ILR granted (BRP) date is 27th Feb 2019, BC application can be submitted online on 27th or 28th Feb 2020.

Please advise

Thank you

Any date from 27 Feb 2020 onwards.

As suggested "Name should be the same as in your passport on and BRP", to correct my surname and to match with rest of my family members, if I submit new indian passport application with correct surname and then update BRP using "Update, replace or transfer your biometric residence permit (BRP)" with passport as proof.

With updated BRP then apply naturalisation so that certificate will have correct surname and same follows with british passport without issues.

Query please:
With new indian passport(without space in surname) and after getting naturalisation (same as BRP with space in surname), can we apply deed poll service for change/correction of name and then applying for british passport with deed poll certificate. does this help to get british passport with correct surname?
(Avoids updating BRP process). If this query does not work, only option to think is above initial points may work.

Please advise