Really, i wouldn't think it would be a problem since the motif is controlled by the fantom which in turn is controlled by the laptop.
One comment regarding this: the current version of FXLC ony controls external keyboards or modules played through the Fantom if you connect those external modules to a second MIDI out port on the PC.
That is, the PC/FXLC combo has a MIDI soft-thru function and by manipulating the MIDI data that is forwarded I have been able to also add functions such as the Octaver (note doubler/trippler), automatic sending of extra Program Change messages when you go to the next 'stage' and so on.
I will probably add an option to allow enabling/disabling external modules even if they are connected direclty to the Fantom (although that would have to be through actual MIDI of course, not USB) but it's not in there yet. It was but I removed it because it was done by manipulating the Fantom's KBD switch. It worked but not perfectly because turning off KBD would also prevent subsequent note-off events or pedal-off events from being transmitted by the Fantom so you could end up having notes hanging if you play them, swich to another stage where that MIDI channel is disabled and then try to release the note. I will have to use another approach, possibly chaning the MIDI channel for the part to something that is not used or setting the Key Range to say C0-C0 or something. I've tested this and it does work, ie the Fantom will still transmit the note-off and pedal-off events for the part/channel.
Bottom line, you will need a USB MIDI interface for your PC if you want to control
both the Fantom as well as other gear using the current version of FXLC. And as I pointed out this setup does offer more features that cannot be implemented if the external gear is connected directly to the Fantom instead of going thru FXLC and out the secondary MIDI port.
Figureing out the live mode was going to enable me to have more favorites if you will.
In principle FXLC does not need the Fantom's storage to store the complete Performance data, it could have it's own storage area on your PC with an unlimited number of Performances which can be sent to the Fantom's current 'temporary' performance. Not sure if I will do this as I don't need more Performances myself at this point than what the Fantom can hold in User and Card memory.