So a completed online app is only 'valid' for two weeks once it has been filled out?
And the timeline would go:
1) Gather necessary docs.
2) Fill out online application
3) Print it out, and submit with all other docs
4) Wait for thumbs-up, and biometrics appointment
Where would the Life in the UK test come in that sequence?
Just to sum up...
If your wife would like to have ILE (***nitpick alert***Indefinite Leave to Enter - ILR is Indefinite Leave to Remain issued to those ALREADY in the UK) she would need to arrange to take the LiUK test before submitting her online application. So a trip to the UK would have to precede your timeline. If she chooses not to do so then she would receive the spousal visa with the KOL endorsement.
1-Gather Documents
2-apply online & pay & schedule biometrics appointment
3-Attend biometrics appointment
4-Submit documents with validated biometrics sheet to the consulate within 14 calendar days of attending biometrics appointment.
5-Wait....
If you choose to go the spousal visa with the KOL endorsement when you arrive in the UK she can take the test at anytime and apply for ILR after she's passed the test and does not need to wait for the 27 month spousal visa to expire.
The most economic way is if at some point that you'll be in the UK she can just schedule a test and take it. Really not that difficult of an exam I've been studying for about 3 weeks now and probably could pass it today if I took it. Then when the time comes to apply for her visa to the UK she'd have the certificate and would just need to submit that with the application resulting in an ILE and her being safe from all the pending legislation changes that will come next year---provided that you are looking to move sometime in the next 8-12 months.