Yes, you can use both together. There are no restrictions.
In SimpleDNS, the records and queries are unlimited. The simpleDNS domain charges 1$ per domain. In the case of the Traffic director, you have to purchase Health Check, additional records, and queries.
- Domain – $2/month per domain
- Health Check – $1/month per resource
- Queries – $5/month per million
- Records – 1K Records are FREE & Additional 1K costs $2.50/month