Just in case you did not see this.
At 344 grams, this lens is a good example that being made for APS-C does not result in a smaller lens (for focal lengths above 24mm-ish). The FE 85 f/1.8 is 371 grams, just 27 grams heavier but including an AF motor.
At $399 its going to have a tough fight against the Sony FE lens at $598.