Hi! Good luck at your 10k! I did my first non-Disney chipped event to submit an earlier proof of time but I will say that no it is not worth it to submit a 10k time if your pace for it is over 16 minutes per mile for the 10k and the reason is that runDisney has Trackshack (where we submit our times to) tabulate 10k times with a formula that estimates your half marathon pace as slower than your 10k.
For example:
Estimated finish time for a half marathon with a 16:00 minute per mile pace is 3:30
Estimated finish time for a half marathon with a 14:50 minute per mile pace is 3:15
But, with the algorithm they use for assuming you would run a half marathon slower per mile than you would a 10k you would have to complete your 10k with a pace of 14:15 minutes per mile. or faster. If you achieve that or faster on your 10k you will have the perfect time to submit, otherwise it may not give you the resulting estimated time you want (the 10k I ran this month was at 15:30 minutes per mile but the algorithm returned an estimated finish time OVER 3:30 which wasn't what I expected since a 16 minute mile should have been 3:30, so now I know for the future!).
Hope this helps! My first half was Tink and I didn't have any proof of time and I wasn't in the very last corral (but second to last) so you never know