Hi cwangv,
Barring an up-coming enhancement in the near future, would you recommend me use a custom XID instead of the one generated by Mango to overcome this issue? for example, I could name an XID as 'METER-1_KWH'. Does Mango software check the uniqueness of XID when it is entered? If it does, I think entering XID by hand can be a solution to this.
I have personally always believed in custom XIDs, and have always encouraged people to think of them as another identifier field. Others disagree with me, and I haven't been able to understand the reasoning presented. Something about more work if it has to change later? I can't say.
Yes Mango checks the uniqueness of the XID. You could generate XIDs for all the points and update them via SQL, or if it's a fresh system you could use JSON import, but since neither CSV nor JSON import can change an XID, you must use the SQL console or change them by hand, which would be the more work to change later argument. But, it'll make the data download more readable without having to wait for the git issue to be addressed, and it'll make any dashboards' code more legible.