Oh, I did read it all. If you use lithium-iron batteries they are safer and don't have as severe a risk of fire as the lithium ion type. Lithium-Iron battery failure involves a lot of heat but not usually a case rupture - lithium ion cell contents expand dramatically in thermal runaway, often rupturing the case and letting oxygen get at the then self-igniting lithium contents.
Lithium iron batteries are still not 100% compatible with lead-acid charging systems. If the combination works for you, go ahead and use them. You are still taking all responsibility. Electrosport is explicitly telling you they will not be liable if something goes wrong.
Electrosport is not specifying what lithium chemistry battery is not recommended. They make replacement reg/rect units to replace factory components, for standard batteries. I'm sure they could make a compatible unit for lithium battery chemistries. So far, I don't think they do.
There's a very important difference between rechargeable lithium and lead-acid batteries - lithium battery chemistry gets really ruined by over-discharge while lead-acid cells will be damaged... but not severely (and deep-discharge designs have lower charge capacity/weight but can handle deep discharging). The minimum voltage for lithium iron or lithium ion cells is 2.5V. Devices designed for them will include a low-voltage shutoff that doesn't allow further discharge and cell damage. There is no way for a bike reg/rect to do that.
I'm unconvinced that there is any reason to install a lithium battery in a motorcycle. The weight difference isn't going to make any worthwhile performance improvement, they cost more than lead-acid, no lead-acid charging system is 100% compatible, and an accidental full discharge usually kills them dead.
