Thank you. I think my difficulty in understanding your post is because there are different grades of murder - DD is a more serious offence and carries a harsher penalty. The intent can be differentiated in relation to the intruder, it is having direct intent to kill under DD, rather than foreseeing the person will probably be killed, DE.
But I can understand that if, as you say, they cannot deviate from what is sought by the State, an upgrade to DD is not on the cards.
I am not sure you have this right to be honest.
DD & DE are not offences. The offence is the same in each case i.e. murder.
Premeditated murder carries a mandatory 25 year sentence.
Murder where not premeditated is 15 years min. This is what OP is looking at.
Whether intention is found to be DE or DD the facts are essentially the same - the intentional & unjustified shooting of an "intruder". So i can't see that it would make much difference to the final sentence whether it was found that he meant to kill the intruder or simply meant to shoot them and did foresee the risk of death
The result and culpability is effectively the same
Personally I think it makes no difference by which intention he meant to kill the "intruder" (not that i believe the intruder thing!)
But i would need to check all this again in the actual statute books.