With the SC1200 the SH624's Security Light On and Off button does the Address you set in the console {House Code & Light Code}.
The KR32A Lights On and Lights Off do the Address you set +1 Light Code. {House Code & Light Code +1}.
So getting both remotes to control the same security lights address, with their Lights Buttons is not possible.
You maybe able to set the the SC1200 Security Light Code to 1,2 or 3. Then have the Lamp Modules on the higher of the two. 2,3, or 4. The KR32A would control them and then the corresponding button set on the SH624 could be used to also turn them On and Off.
On an alarm the SC1200 sends a On and Off command to both the Address it is set to and the address + 1 Light Code. So it would still flash.
You can still use the 1-4 buttons for lights on the same house code and units 1-4. The console will transceiver the RF from remotes on the house code it is set to. If you change the house code on the SH624 from what the consloe is set to. The signals will not be processed and you would need an added transceiver set to the other house code.