ElectricGod wrote:The only implication is the fact that LION charges to 4.1 volts rather than 4.2 volts.
That is wrong - 18650 cells charge to the same 4.2V as Lipo puch packs.
The much more important difference is discharge voltage. Liion can be discharged to ~2.5V while Lipo should not be discharged below 3.2V.
As long as you keep the entire set between 4.2 and 3.2V you should be fine though.