Yes
You can do it w/o a gauge or with a gauge that has a "T" for that purpose..many FP testers come with a flow port. I just made my own and anyone can by just making a T in the fitting line for the gauge ..then you can do both at the same time.
It is smply to see if you have a good flow.
As some guys have stated, you can have a plugged up filter that will get you spec pressure at a gauge , but the flow rate can be way off b/c a pressure reading does not equate to a good flow. And a good flow does not always mean you have a good/high enough pressure.
If engine demand is higher than the flow rate, the fuel volume can not keep up to the demand.
[ i.e. if you had a kink in your garden hose , you can still have pressure at your nozzel, but as soon as you opened it up full blast .. you could have very little flow rate. Once you turn the nozzel OFF, the low flow rate will allow the pressure to build up again in a short time, but you still have NO VOLUME., as in a partially plugged filter. Another example would be filling a 5 gal bucket up with a small dia hose and a large diam hose that both had the same pressure..which is why they don't use garden hoses on the Fire Trucks ..
Your fuel system needs BOTH..and no air in the feed line.