MessagingService would probably be less efficient than an OrderedDataStore. You can use data stores past their budget - all the budget means is requests following will be subject to throttling.
With MessagingService, you would need to send the data, get the data, check the player there already exists, update their data there, and if requests are at all delayed and the player joins back to a different server (leave and insta-rejoin), it could cause some big issues. OrderedDataStore would probably be better. Cool idea!
Uh what do you mean, how am I supposed to implement it to my code? I mean as for now I went back to the old working script but meanwhile I’m still trying to fix the one you try to help me to fix.