The last game was nothing to write home about either. Conceptionally I find it rather weird to play 1…d5 if you have the Sicilian in your repertoire, but apparently he likes his d5-systems. The resulting variations lead to Slav/Caro Kann structures and should not suit a dynamic player at all though. Here is how such positions in the Oberliga between a veteran GM and a FM usually play out: Black gives up the bishop pair, white slowly impoves his pieces, gains space, creates a weakness, wins a pawn and converts.
With a performance of 2430 Keymer sadly showed once again that he is currently not underrated and that is exactly the problem. Now let’s assume he went for the Drawmeister (Qc2-Nimzo etc.) except against the unknown dude instead. It would/could/should have resulted in +1 against an average of 2588, which should be a 2600 performance. If his opponents play for a win and overpress, he could have scored even better. Tournament strategy is key!
Note: This is not some wiseguy comment from an armchair quarterback. There is a clear difference in going for dynamic imbalanced positions and keeping things under total control. Nobody prevented him from playing the Berlin and the Ragozin as recommended by Leela. Nobody prevented him from going for forced draws with white either. It was a concious decision to go for positions where the onus is on him to prove something.