How to *safely* enable automatic initialization cell evaluation for one notebook?

Question

I want to configure this one notebook (let's call it X) so that its initialization cells get automatically evaluated when X is first opened¹.

To this end, I have applied the settings shown below to X:

InitializationCellEvaluation -> True
InitializationCellWarning -> False

Still, I get warned about X's initialization cells when I open it.

I understand that one way to do what I want to do entails disabling a "global security option", like so:

SetOptions[$FrontEnd, GlobalInitializationCellWarning -> False]

Nevertheless, it seems to me a bit excessive to reduce Mathematica's security globally just so that I can enable automatic initialization cell evaluation in one notebook.

Therefore, I'm looking for more limited ways to achieve the same thing.

(E.g. some way to invoke Mathematica that disables GlobalInitializationCellWarning just for that session.)

FWIW, I'm using 10.4.1.0 Linux x86 (64-bit).

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^{1 This probably should go without saying: the automatic evaluation of the initialization cells should happen even if the kernel is not yet running; IOW, the rule I want followed at this notebook's startup is: "If the kernel is not yet running, start it; then, evaluate all the initialization cells". If this is not possible at all, then the rest of my post is pretty much moot.}