Hi Craigory0055, I hope your day is going well.
Yes, if you are using dollar cost averaging, you still want to track your cost (basis) and amount of BTC received per transaction. You should always keep good detailed records of your purchases because each sold transaction must have a record of basis. If you do not have record of cost, the IRS considers your cost to be $0.
You can choose which accounting method to use FIFO, LIFO, HIFO which ever creates the best tax outcome for the year. (suggested to use the same method each year)
I added a link to allowable accounting methods
https://coinledger.io/blog/cryptocurrency-tax-calculations-fifo-and-lifo-costing-methods-explained