I am going to disagree with you slightly here: my experience (backed by others as well) is that a test print which gets blasts of 2+2+2+2 seconds of exposure is not the same as one 8 second exposure. This is because the bulb takes time to turn on, come to full power and then turn off in addition to mechanical delays with all timers (including electrical ones). I have taken to making test strips (I cut up an 8x10 into 10 - 1" strips which are 8" long) and then making a 2s exposure, a 4s exposure, a 6 sec exposure, etc. in order to decide my base exposure. While this seems a waste of paper, the number of times where my 2+2+2+2 givens me a print which is too light/dark and I have to make another print, more than compensates for this "waste". I write on the back of the test strip (before I even expose them) how many seconds it is, so I can keep them organized after developing.
The other option is to have a "running test strip", where you set the timer for 20 seconds and just move the covering paper every two seconds, so the bulb on/off delay does not affect the print.