I've never shot mine, and don't plan to, either.
There is no prize for getting the bullet as close to the sensors as possible. Shoot up into the top half of the available area under the screens, and you should never come anywhere close to hitting the chrono.
I never planned to shoot my chronographs either but both happened when I got in a hurry to finish before a couple of rain storms. One was a 45 ACP M1911, the other a 204 Ruger rifle. Haste makes waste.
An update...
I'm liking the LabRadar. I'm finding it quicker and easier to set up than either a typical optical chronograph or a Magnetospeed. (I shoot out back so I do not have to compete with other shooters at public range.)
So far, the only miss-read that I have had was when I did not arm the unit. I do wait to see the current shot data on the screen before shooting the next. I've collected 30-40 or so strings of data, mostly handgun since I acquired the LabRadar.
Aiming the unit is crude but I have not had any issues. I just take time. But, some kind of aiming aide would make it easier. A longer sight radius would be helpful.
The LabRadar stores data in .csv files (comma separated values). They use a semi-colon for the delimiter, which I understand is fine for Microsoft based software but does not work with Apple's Numbers. So, I have to rinse the file through a text editor to change the semi-colons to commas. Then the file loads in Table format in Numbers. The files include a summary file and then a data file for each shot.
I add some information to the Numbers file and print it out for filing.
The down range data is interesting but I have not really found any use for it yet. My range is only 100 yards, so a 130 yard limit is not a restriction for me--yet.
In reviewing the data from the LabRadar and previous data from other chronographs, I have been seeing some discrepancies. I'm not sure if it is different dates and conditions or something related to the instruments. I'll probably set up a second chronograph and collect data from the two chronographs simultaneously.