There are thousands of IR's of the same speaker, and even if the same microphone was used, they can be very different.
When you or the sound technician mic your cabinet..the resulting sound is always different. So I guess these IRs will make your foh sound only a little bit more similar to your cabinet in the room sound, but maybe not. This is only an opinion, I dont know how representative of the whole cabinet (not the microphones and position) these IRs are.
What I do, my recomendation is, to check the compatibility of the sound of your cabinet and the line out sound, a/b ing them (with headphone or flat speakers). If you dont have a very flat reference dont worry (if you know very well how it sounds) but better try several references just in case.
Compatibilty I mean similar bass amount specially.
Lately i am mixing the cabinet and the monitors of my rehearsal place, very close one from another and it is ok, nothing weird..and my favorite rig is an studio rig, i dont even know the speaker. Kemper does a good job spliting an studio rig, i can't notice when a rig is merged or studio through a cab.