It probably doesn't much matter if the minimum burn time during hot water calls is at least a couple of minutes. If the boiler is only getting ahead of the heat exchanger once in awhile it's not a big deal. If it were happening often or every time, it's worth dialing back the flow or taking other measures on the primary side to prevent it.
If it's simply a matter of punching in a number into the setup on this boiler, go ahead. As long as you're not running out of hot water, the lower the firing rate the better. Running the boiler at a lower fire modestly improves the combustion efficiency of a mod con.