Typically you see infotypes for ESS UI are decoupled. You should be able to achieve your requirement without decoupling Note you can create any custom infotype as decoupled.This means, a CHECK class should be provided in view V_T582ITVCLAS.It is not necessary to have huge code inside this class; even empty implementations should be fine, important is to have this class implement some methods in principle. Of course, if the custom infotype has its logic in module pools, that needs to be incorporated into the BL class. Note that Basically there are 2 "HR masterdata frameworks" that (technically) handle the masterdata maintenance: the 'old infotype framework' (OITF) and the 'new infotype framework' (NITF). O ITF comprises the user exits ZXPADUxx and the BAdI HRPAD00INFTY. It is called from standard transactions PA30/PA40 etc. NITF uses enhancement spot HRPAD00INFTYBL. NITF is called in the Concurrent Employement environment for certain infotypes (see T582ITVCLAS, field NITF_ADM) during PA30/PA40 maintenance and by certain applications like HCM Processes&Forms and ESS. This means NITF only uses enhancement spot HRPAD00INFTYBL HCM P&F only uses the new infotype framework hence ZXPADUxx and BAdI HRPAD00INFTY are NOT called via the NITF.
not recommended to change permisssiblity of standard infotypes as it ll cause dump.