So I'm bored out of my mind studying for exams and decided to search up on Merc engines. My opinion with my basic knowledge in engine engineering is that the M111 specifically the 2L should be a very good at high power engine NA or boosted.
The bore and stroke is 89.9 x 78.7. This means the large bore and short stroke should mean that the engine could be pretty good at making power. By increasing the compression and head flow, the M111 should excel in NA power performance. Though there are no balancing shafts, balanced components should suffice. Must performance engines have them removed anyway.

Going towards the boosted setup, the low compression nature of the engine (9.6:1) Should also mean that it will be very good with boost.

The M111 engine is somewhat designed for reliability; with its larger bore to stroke ratio, low ish max rpm, low compression and low airflow.
Smaller stroke means lower amount of cylinder rings to wall drag.

We can make advantage of this engine design by increasing airflow, which means head work, balancing the engine parts, exhaust upgrades etc. This should mean we can increase rpm limits.
Increase compression for NA goodness
or
Keep compression ratio for BOOSTED fun.

Now I'm not a expert at this, I just happen to know a little. More than welcome to correct me if I'm wrong; I'm always happy to increase my knowledge.
Opinions Welcome!