There's a comma that shouldn't be in your text; "Zur Auslegung dieser Klausel kommt (, ) man also gar nicht, erst recht nicht zu verbleibenden Auslegungszweifel", so your question should have read " kommt man also gar nicht".;

Your sentence reads something like this:
"For the purposes of interpretation of this clause/ due to the layout of this clause you're even less likely than ever before to come across any remaining doubts as to its interpretation"

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Note added at 2 hrs (2016-03-30 10:10:11 GMT)
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This is a positive validation of the layout/ interpretation of the clause which is confirmed by the second sentence, i.e, that the defendant's assertion has been upheld, by the positioning of the ( contractual) performance period clause elsewhere in the contract other than under the heading of bank guarantees;