I wonder if Duplicolor engine cleat coat would hold up better than the stock coating:
http://www.duplicolor.com/products/enginePaint/

Step 1: Put on long rubber gloves.
Step 2: spray green scrubbie pad with oven cleaner.
Step 3: scrub side covers.
Step 4: wipe clean with a rag and small bucket of water

Step only have to do once if you do it right since your side covers are now etched... paint side covers with silver drum/caliper paint. Let dry then ride until the paint stops stinking and reapply paint while the covers are warm. Hubs, rotor hats and calipers get hotter than your side cases should.

If you know any truly fossilized boat enthusiasts ask them for some steel hull primer. Don't get any on you, don't breathe the dust... very high lead content. Lead oxides will seal up the aluminum. Thn you can paint over it with impunity. My truck engine was painted with aircraft enamel in 1958 or 1963 (forget when the engine was swapped) and is still holding on tight. Aircraft and boat paints from back then are high lead. Don't get caught with it, but if you can find some it is worth every penny.

The drum/caliper paint is more chip resistant than the engine clear coat? If so, this seems like a good solution once it warms up around here. I don't really want to work too hard on this (sanding and buffing the aluminum), but I also want it to look decent.

I've only ever used it on Peterbilts and Freightliners. Seemed to hold up fairly well.

Problem with the side cases is they are hanging out there for all the world to see and make contact with. Unfortunately, good engine paints got banned a couple decades ago during the country's big "lead is evil" scare. My 1963 Honda Scrambler still has factory engine paint on it with about 80% coverage intact. My Savage cylinder and head was painted with Duplicolor engine enamel in 2000 or so, properly cured but not primed. It held up really well for about 10 years, still has 90% coverage but it is starting to get ragged.

Engine enamel over engine primer will likely do you fine. Just don't waste a bunch of money on clear coating. The key to getting a good bond is heat. Warm the engine up for a couple minutes, put your first coat down. Let it dry about 20 minutes, go on a short ride. Come back and when you can touch the engine with bare hands (coffee cup temp or so) paint it again.

Even easier way to deal with it. Order some ZOOP Seal from the internet, follow the directions. Completely seals the pores of the base metal, no painting required. Used to use it on hot rod billet engine parts. Pricey, but it lasts for a long time.

zoop has changed their name... don't remember what it is.