The first option is better because you pay no fees while the second option may be better If you want to claim coins that are not supported by Coinomi and have a decent value.
there is a big difference between these two though which is worth mentioning.
using Coinomi, you still control your private keys and they stay on your device so the risks are lower. but using that digging service you give up control over your private keys and although
the service seems fairly legit i still would use it as the last resort.