This. I'm not sure why L2 is even being discussed at such a high level. I've worked for Tier 2 carriers and have deployed fiber across multiple states (transport) and have experience dropping out into FTTH solutions. The last thing you want is an unscalable L2 dependent solution that's a royal PITA to debug when things go wrong (and, they will).

IMO one of the core components to think about when doing a buildout is your total solution. I've worked with Infinera in the past for both long haul and PON solutions and the important thing is getting the most return on investment out of your deployed glass. DWDM / band splitting is where you really need to engineer up front.