Hey there. I really don't believe in the magnifying idea for the following reasons:
1. You concentrate the light into a too small area. You would increase the light intensity (PPFD) by several times in a tiny area while reducing PPFD over a larger area.
2. There's no way you can accurately measure how much you concentrate light so the risk of burning parts of the plant while depriving others parts of the plant would be almost guaranteed. I mean, you know kids using magnifying glasses and sunlight to kill ants? You'd have the same scenario. That high light intensity is not helpful at all.
3. It would be a practical nightmare to set up, angle, and keep all the magnifying glasses fixed.
So yes, it's definitely possible to give plants too much light. Generally speaking, beginners should aim for around a PPFD (PAR) of 600-800 µmol/m2/s. After you have mastered nutrients, temperature, humidity, etc, it's possibly to increase PPFD further a bit without burning the plants.
Find a grow light that gives as high PPFD distributed as evenly as possible over your grow area. The grow light's manufacturer should provide PPFD data for the grow light you own.