There really isn't much difference in the fermentation between lager and ale yeasts, just the temperature. If anything, IMO, a lager would benefit more from the longer primary. Fermenting at cooler temps will keep the yeast a little slower to clean up their by products. With the cooler temperatures, the longer primary time definitely won't hurt the beer. Almost all my beers are in primary for at least 4 weeks.
Draft 1: Lightly smoked Weizen
Draft 2: Belgian Wit
Draft 3: Rauchbier
Primary 1: German Scwarzbier
On Deck: Belgian Brown Ale, Pale Ale, Stout