TLDR: The excerpts confirm that certain literal information may be modified or deleted “at any time.” They do not confirm that you can modify an entire online return after its electronic signature.
What the sources confirm about the signature
When you file your income tax return online, it is signed electronically. However, the available excerpts do not specify the effects of this signature on the possibility of making subsequent modifications.
Information that may be modified
For the literal information entered in the main return, you retain, according to the wording cited by the source, the possibility of modifying or deleting it “at any time.”
This indication concerns the literal information in the return. It does not confirm that you can modify all declared items, nor that this possibility applies after the electronic signature.
Scope of the answer
The expression “at any time” is linked to the literal information mentioned in the excerpts. It is not presented as a general rule authorizing the modification of an entire return that has already been signed.
The excerpts do not provide a procedure, deadline, or specific form for correcting a return online after its signature. You therefore cannot infer from these elements alone that a general modification remains possible after the signed filing.
Conclusion
The answer is limited: the sources acknowledge the modification or deletion of certain literal information in the online return, but they do not confirm that you can modify your entire income tax return after its electronic signature.