The phrase "additional optional" is correct and can be used in written English.
It is used to refer to something that is not required, but is available as an additional choice. For example, "The gym offers additional optional classes such as yoga and Pilates."
In addition, I can provide additional, optional data like my blood type, address, primary contact in case of emergency, any medication I use, allergies I have, and more.
"The academy has two Islamic faith assemblies each week and additional, optional Friday prayer.
"Additional optional controls, such as room lights or television, may be similarly installed in control panel," Mr. DeHart writes.
Shortly before jury deliberations began last Thursday, Judge Baxter gave jurors additional optional charges to consider if they acquitted Mr. Trantino of main charges of aggravated assault and criminal restraint.
His version may be tight: his draft calls it an "additional, optional instrument" that will apply in the first instance "only to a very limited number of immigrants".Mr Schily would like his plan to become law next year.
An example campaign with seven missions between 2025 and 2038 and two additional optional missions is provided.
It offers many additional but optional tools, so that the compression ratio will significantly vary for different implementations.
But your friends don't have to join Livestar to rate restaurants, and a review can simply be 1-5 stars, with additional notes optional.
Additional petals optional.
The assignment as a tutor was regarded as an additional and optional activity.
They thought that most vaccines are either manufactured from a virus or from artificial chemicals; therefore, they felt reluctant about taking their daughters to receive an additional but optional vaccine: Vaccines are made from viruses.
