Has anyone set up 4-5-4 accounting periods in NS? Not 4-4-5. If so, do we just manually create Base Periods, so we can modify the Start and End Dates

Yes

Did you encounter any issue with FAM module, ARM module and consolidated exchange rates, etc.? Or it just works fine

Sorry I should be clear. I haven't done 4-5-4 months, but I don't see any reason it should be any different than 4-4-5. Core functionality should work fine, but you're right that you'd want to check on FAM, ARM, amortization if you have it, maybe allocations if you have them. Basically anything that's kind of ancillary. As I understand how Consolidated FX rates work, I don't think there should be any issue there. But I'd obviously test heavily on all of the above to see one way or another. Re: FAM specifically, you'd probably need to spin up a new depreciation calc. I think there's an out of the box one for 4-4-5, but I don't remember how that calc works to know if it would work for 4-5-4. You might have to do a Save As on the 4-4-5 one and tweak the calc.

Thank you!