This makes it look like getblocktemplate can take some options, but I'm having a bit of difficulty puzzling them out to see if I can get it to do what I want it to do. If I could get it to just return a coinbase transaction without gathering up a bunch of transactions from the memory pool, that should run much faster and would be more feasible to call as needed to get the included coinbasevalue. Is there some invocation of getblocktemplate that will do this, short of tweaking the *coind config file's block-generation parameters (which would most likely be a Bad Idea on a mining-pool rig)? It looks like sigoplimit and sizelimit might be able to control this, but whenever I try something like this:
bitcoind getblocktemplate "{\"sigoplimit\":\"-15000\"}"
the result is no different than without the parameters. Is there something I'm doing wrong here?