Etsy gives a listing two option types
If your till sells size, colour and material, one of the three has to go.
Etsy permits two option types per listing and will not stretch. A product that the Clover till sells by size, colour and material has to come down to two before Etsy will take it, and choosing which two is a question about your catalogue rather than a switch anybody can throw. Merging two of them into one option with a compound name is the common answer, though what you call it is yours to decide.
Do this before stock starts moving. Reshaping variants on a live listing means the SKUs underneath them change, and every SKU change is another chance for the two sides to stop recognising each other. An afternoon deciding how a three-option product should look on Etsy costs far less than untangling counts that drifted apart around a rename nobody wrote down.
Clover has no equivalent limit, so nothing needs to change on the till side. That is the general shape of this pair: Clover is the roomier of the two on almost every measure, and Etsy is where the rules come from. Read Etsy’s constraints as the design brief and the Clover side will accommodate whatever you decide to do.