Citizenship: 90 days final year count

[homeOff]

Hello,
I find the forum very helpful but in the plethora of topics cannot find certain information.
As an EEA citizen I am awaiting my PR card. Once this done I want to apply for the naturalisation. All boxes seem to be ticked but I am a frequent traveler and 90 days in the final 12 months as a test of residence is a bit of challenge. I am not in breach and will not technically get any close to the other limit of 450 days in the 5 year period. I am aware that at the discretion of the HO 90 days cap can be exceeded but do not want to rely on the will of the underpaid (long list of undiplomatic adjectives here...) HO staff.
The questions than:
1. When the citizenship application sent (I will do it via NCS) - when does the last year, 12 month test triggers?
Of the choice:
Date of application?
Date of receipt by UKVI/HO?
Date of acknowledgement?
2. Once such date set, can I travel excessively beyond the 90 days cap (as that one can be actually calculated up to date)? Or, should HO process take months, would I need to wait before risking extra journeys abroad?
Waiting for the final approval may turn the service into Home Arrest rather than Office...
Thank you inherently for an advice.
Michal

[LilyLalilu]

12 months preceding the date of application which, if using the NCS, is the date of your NCS appointment.
No limit on travel after that as far as I am aware - just ensure you are home to do the Biometrics and have someone check your post while you're away.

[homeOff]

Thank you.