My personal opinions & first thoughts about Beam Chain.

The idea is simple; 

We have too many possible improvements on the L1 consensus.

However, we don't have any dedicated "paths" to move forward and get these improvements on the L1. 

Beam gives an overview & possible paths to get needed improvements to ETH L1 consensus.

The beam chain is an independent chain that works simultaneously with the Beacon. After getting all the improvements and tests done, the Beam chain will be replaced (or merged, idk how to call it) with Beacon. 

This refers to a "batched" subset of optimizations on Ethereum.

The idea is great, and I'm sure ETH devs will execute it perfectly.

However, the idea of continuing with the same Beacon chain until 2029 does not seem to be the best thing we can do.