I said what I said more as I think most people would get quicker results with the combo method, as they probably have their patches most of the way there with a near field or near field mix already and are just missing a little bit of something to make it pop in FRFR. When I had a XiTone in my possession for a couple of weeks (borrowed), this was how I was most happy without needing to touch the VST amp settings I had sent out to the X7. I feel that this reflects the concept that most have for auditioning IR's - one gets the rest of the settings the way they think they like or is close, then use the IR to tune the sound further, instead of the other way around which more often than not should probably be the way that it's done. Assumptions of course on my part, but based on lurking observation.
If you have built your patches, approach, and playback monitoring around the use of the stock FF's, I don't think you should have much issue in transition to the use of these. While I do not have an Axe I or II to compare against (speaking frankly, I'm too broke for new gear purchases after having our second kid for a long time for anything requiring a substantial investment), I had at some point found some of Jay's FF's in a zip file somewhere on this forum. While there are obvious differences in speaker, cabinet, technique subtleties, possibly outboard gear, etc, I opted for a sound that you could say would be somewhat of a middle ground between his On Axis and 30 Degrees IR's. By middle ground, I mean conceptual median, not what the two would sound like summed, as there is certainly a difference in the two. As with the bulk of my approach, I don't so much dabble in extremes as I do small variations of what I think is the sweet spot, so there will not be the huge variation in response between positions 1 to 5 as you would get going from aforementioned On Axis to 30 Degrees JM FF. To that extent, if you want some of that overly rumbly bass to blend in, Back-of-Cab has got your back, or maybe even the mid-field Floor positions if that is too resonant sounding, leaving you with only the need to possibly boost some treble in your patch, and that it's a maybe, not sure what you have dialed in right now nor what you're using and how it would compare with what I did.
Hopefully this was helpful?