You can absolutely request return of passports in your situation. Requesting return of PASSPORTS has NO negative bearing on processing of your spouse's ongoing RC application other than sometimes it may cause DELAYS to the decision making process! However, you must make sure when your complete the online request for passport return, Select NO when question asks 'Do you wish to withdraw your application'. (This question will appear under 'Get Started' tab when you start to complete this online form)
The online official link to request return of passports/documents is this:
https://eforms.homeoffice.gov.uk/outrea ... ments.ofml
I strongly recommend that you go through each tab of this online form carefully, its very simple and user friendly though!
When you reach the last tab, on the bottom you will find the SUBMIT button and also a PRINT button! BEFORE you hit 'Submit' button, Press the 'Print' button and all the completed form could be saved in PDF format bearing date/time of submission as well. This will serve as a useful review tool before you hit Submit and also serve as a record for you)
In regards to link you mentioned in your post, that should not cause any concern. When you complete this online form, you will find under Declarations (Its maybe the second last/last page) the following text:
''if I am the main applicant or another applicant and I am subject to immigration control (i.e. not
settled or an EEA national or the family member of an EEA national) and I have requested my
travel document for identity purposes I understand that if I use those documents to travel
outside the UK, Republic of Ireland, Channel Islands and Isle of Man my application may be
refused, voided or withdrawn and the fee will not be refunded. I may also be unable to re-enter
the UK; '' (Copy/Paste from Declarations section of online documents return request form)
Good Luck!