Hello @Dashboardb. Boost Mobile does not have data rollover. If you would like to use 10GB more, you will need to restart your plan. If you still need assistance, send us a private message with your phone number and PIN to further assist you. You can send us a private message just clicking on my name and then selecting “Send this user a private message".
No it does not give you usage of the extra 10gb now. If you run out early it will not automatically reset for you in the middle of the cycle, you must add additional data by if account already has funds) restarting your plan immediately which will reset your bill cycle that day and give you immediate access to the other 10 gb. It's unclear if buying the 1 gb for $5 or 2gb for $10 will get your speed back to 4GLTE if your plan itself is depleted. Perhaps a boost Rep could clarify this.