I have a road bike with triple crank 30/39/50, and 12-27 cassette, but I'd like to lower the gearing a bit. I am thinking of replacing the 30 chainring with 28 tooth, maybe even 26, so this way I can keep the closer spacing of my 12-27 cassette while affecting only the lower end. With the 30T ring, I get 29.7 inch as the low gear, and the smaller rings will get down to 27.8, or 25.8 inches . Additionally I think I also won't need to add links to my chain. This however, is out of spec for the 5600 FD because it's spec'd for 30 as the small ring. With the 28 chainring I'm at capacity of my 5600 med-cage rear derailleur and 26 chainring I'm 2 over. However, I think as long as I'm not using extreme crosschain combo like small-small I might be ok.

Does this sound like it could work?

The other option I thought about was a 12-30 cassette which exceeds the maximum big sprocket for the RD (27T) and capacity by 1. Also there is a bit more spacing in the middle of the cassette where the 16 is traded for 30, so instead of having 12,13,14,15,16,17,19,21,24,27, it's 12,13,14,15,17,19,21,24,27,30. Would I need a couple extra links on the chain if I go with the cassette option?

How much room around Shimano's spec do I have to play around with? Which option sounds better, kinda leaning towards the smaller ring right now vs the cassette.