Why on Earth should someone be required to run a full node just to transact?  Especially transact on the LN, which is a second layer solution. If the developers of LN went that route, an alternative second layer solution would be offered. After all, the original white paper already laid the ground work for SPV nodes. People should not be required to run a full node unless they want to. Furthermore, the problem is not keeping up, it is trying to catch up if you have to start from scratch. It already takes most people who run a home node several hours, if not days to complete the verification if the have to start from scratch. If I were a potential new user and wanted to try out the LN to buy a cup of coffee, I would probably lose my patience in several seconds. Not many are going to be willing to wait several hours or days to explore this payment option.
   I suppose that a blocksize increase to 8 mb with a 3% increase per year is okay. However, good luck getting anywhere near a consensus on that proposal.