I don’t use pneumatic tools, but I recall an article in Fine Woodworking some years ago about using a large auxiliary air tank to get more working time out of a small compressor. The compressor pumps the big tank full of compressed air (and that might take a while at first), then you run your tools off the big tank, which is topped off as needed by the compressor. Continuous use will drain the tank of course and outrun your compressor, but you will be able to work longer. The idea is that tanks are cheap, while burly compressors are expensive.
Speaking of which, it always puzzled me why compressors are described by the size of the tank, and not something like rates of compressed air delivery (at some specified pressure) or just horsepower. I know the tank affects portability, but if a compressor doesn’t deliver enough air, then it won’t do the job. Am I missing something?