if it could be any help in here, here's how this heck can be done in BW4/HANA based systems:
DATA(is_bw_cloud) = SWITCH #( cl_rs_utilities=>get_is_cloud_bw4_system( i_read_from_db = rs_c_true )
WHEN abap_true THEN 'CLOUD' ELSE 'ONPREM' ).