First of all, I agree with tchrist. I prefer his formulation:
Because it will have fewer features than the actual standard system, performance will be better.
But let me answer your question.
Part I: Assuming the strict rule
The problem is not that due to is not allowed at the beginning of a sentence. The problem is that due to must modify a noun or a nominal phrase, indicating the thing that is explained. It should be replaceable by caused by, rather than by as a result of, because of or on account of.
In your example, it's not so much the performance that is explained, but the improvement in performance.
Therefor, this is allowed, according to the strict rule:
The improvement in performance will be due to the lower number of features it will have compared to the actual standard system.
It's possible to start a sentence with a Due to …, but you have to make sure that the subject of the sentence is the noun or nominal phrase that is explained.
Since this is allowed:
An improvement in performance, due to the lower number of features it will have compared to the actual standard system, will be noticeable.
this is theoretically also allowed:
Due to to the lower number of features compared to the actual standard system, an improvement in performance will be noticeable.
However, people still might read this as if the noticeability of the performance improvement is explained by the "due to" modifier, rather than the actual performance improvement (which is what the sentence literally says, if the strict rule applies).
Which brings me to…
Part II: Is the strict rule an actual rule?
This has been answered elsewhere. Let me repeat TrevorD's upvoted answer:
Chambers Dictionary has the following explanation:
It is sometimes argued that, because due is an adjective, due to should have a noun or pronoun that it refers back to (an antecedent), as in• • Absence from work due to sickness has certainly not been falling (where 'absence' is the antecedent)• . This argument would disallow sentences like:
?• A special train service was cancelled due to operating difficulties (where due to is effectively a preposition).
This point of view is based on the word's behaviour in its other meanings; in this meaning it has taken on a new grammatical role that is now well established. Due to often refers back to a whole clause even when there is a notional antecedent, as with 'starvation' in the sentence• • Out in the countryside, two million people are at risk of starvation, due to the failure of the harvest.
RECOMMENDATION: it is correct to use due to in both the ways shown