FortiSwitch SFP+ to 1G SFP

Hello,

Is it possible to establish a fiber link between:

• a FortiSwitch SFP+ port using a 10G SFP+ transceiver
• and a third-party switch using a 1G SFP transceiver

by forcing the FortiSwitch interface speed to 1G?

• I would like to know if:
• SFP+ transceivers on FortiSwitch support 1G operation
• or if both sides must use the same transceiver type/speed (SFP↔SFP or SFP+↔SFP+)

Has anyone tested this successfully with FortiSwitch and third-party switches?

Thank you.