With two weeks, don't overkill yourself. Best plan would be to revisit your
MGMAT mocks and review them completely - find different methods to solve a single problem, post the questions or search in the forum and you will find different explanations. Have a look at those. Take notes and make flash cards - any tips/shortcuts/patterns/things you find difficult like cheatsheet. If you review this way, it will take 2 to 3 hours to finish the quant section alone and one week will pass. You will be honing what you have learnt so far. That would be the best idea. Solving tough problems won't get you to Q50. If you manage to score a 48 in GMATPrep, then you are comfortable in all the areas, your mistakes will mostly comprise of misinterpretation/careless errors/wrong approach+timing - reviewing the problems is the best way to reduce that.
GMATClub tests are good but going for them in the last two weeks is totally your call as said by the experts. Anyway try them, if you are convinced with the tests, don't try to cram everything within the two weeks. I did that mistake in the last two weeks (not the
GMATClub tests, but put in more effort in the last two weeks) and on the test day was like 'let's get this damn thing finished off'. If you are so confused try bunuel's signature problems - compilation of tough problems with bunuel's explanations - Look for his posts in quantitative section. They are quite good with awesome explanations.