Would have to see the query plan to be sure, but it seems like SQL may be doing an implicit conversion on the date column, which would cause big performance issues.

The safest way to code it with a literal would be this:
(scheme.efg.PAL_date = '20190403')
assuming that PAL_date is any type of date column: smalldatetime, date, datetime, etc..  Then SQL will convert the literal to match the table column and never vice versa.