I usually do 2-5 hours and wait a minimum of 2 weeks before testing the first time. I find that 4 hours of smoke and 4 weeks of rest is my sweet spot.
However, the level of desired cheese smoke is a VERY subjective thing that you will have to try out for yourself.
What several people do and I would suggest is to cut some smaller chunks of cheese that can be used for an experiment, start smoking, and then take 2+ pieces out at 1 hour, then a couple more at 2 hours, 3 hours, and then 4 hours. Label them accordingly and then start taste testing them at 2 weeks, and then depending on how many pieces per hour of smoke you took out, do a taste test every few weeks and compare. This will help you determine the level of smoke you prefer. I have seen this suggested on a couple of other sites and the logic makes sense to me.
If I need my cheese in a relatively short time (1-2 weeks) I only smoke for 1-2 hours. But, if I am able/willing to let the cheese rest in my fridge, I think I get a deeper more flavorful smoke from a 3-4 hour smoke that is able to rest for 1-2 (2+ months if you can) months or more. I have some cheese in my fridge right now from last Fall that tastes awesome! I am going to try to keep a couple of packages until next fall and let it age even further.
Note - The cheese that I age are the hard cheeses like cheddar, gouda, jarlsburg, etc. On the other hand, soft cheeses like Mozzarella, String Cheese, etc. should be smoked for a shorter time (1-2 hours) and consumed within 1-2 months.
These are my 2¢ anyhow.
