I happen to have a Seeed Grove BME680 lying around, and looking through the (Arduino) code for SAM Firmware, I find there is code pointing to Adafruit BME680 library (although that library not included in SCK build).
Its unclear what I am looking at here. The Adafruit board has pinout for I2C interface but no grove connector, whereas the Seeed Studios version has the grove connector. It would be necessary to warm up the soldering iron to use Adafruit board. Not sure what other qualitative differences there might be, but the obvious question is can the Seeed Studios BME680 board version be supported ?
Secondly I see that the Adafruit library contains some of the Bosch BSEC library for BME680 but not all of it. The current version of BSEC library has some proprietary precompiled archive code, and for it to work, there has to be a version prebuilt for the processor at hand. Also, the Arduino CC has difficulty building the code containing references to BSEC library (and) I found it was necessary to go back to version 1.8.9 and make some changes to the arduino platform code for specific MCU to have it compile properly.
Thirdly I ask myself why you bothered to include support for BME680 at all, given you already have a perfectly good equivalent Gas/Environment sensor already integrated into SCK kit. Is it intended to run the two sensors along side each other (for comparison maybe).
What happens when you run both at the same time? Does the code average out the readings ?
My own observations indicate readings from the inbuilt sensor and the BME680 are roughly equivalent in any case.