99% of DIY CNC users don't use Cutter Comp, because they have their CAM software do it. That's why UCCNC didn't have it.
But, as I said, it's being developed, and should be available soon. (I've seen some screenshots of a comped toolpath).

I didn't say you can't have the features of a 25 year old control for $300, I meant a current $10K control.
Yes, hobby controls can do a great many things that high end commercial controls can do, for a fraction of the price.

As for the Lookagead. There's a lot more to it than just how many lines it looks ahead. Different controls have different methods to determine how they follow the commanded path, and how much they are allowed to deviate from the path. The trajectory planner can make or break a control.
If I had to guess, I would expect the Centroid planner to perhaps be a bit better than UCCNC's, because it's been around a LOT longer, and it's been known as a higher end control. But I also know that UCCNC's planner is much better than Mach3's.