Tomorrow morning turn off Dictation and Siri
Let the phone run as normal for 24 hours
Next morning screenprint the 24 hr battery graph in Settings Battery
Immediately afterwards re-enable Siri and Dictation
Let the phone run as normal another 24 hours
Screenprint the Battery chart again
Paste the 2 pieces graphic evidence of extra Battery drain here.
Scientifically it needs to be done several times but one set of graphs would be nice.
Until then we have only anecdotal evidence that this is more than a cosmetic feature.
With the evidence it can be presented to Apple,
Only SE owners can provide the evidence.