Optimize 'VALUES...UNION ALL...VALUES' to a single 'VALUES' the IN-list contains CAST and it is converted to VALUES

with
t1(a,y) as (select * from (values (1, 2), (3, null),(7369,null),(7499,30),(null, 20),(null, 5)) as t1)
select *
from t1
where (t1.a,t1.y) in ((1, 2), (3, null),(7369,null),(7499,30),(null, 20),(null, 5));

EnumerableHashJoin(condition=[AND(=($0, $2), =($1, $3))], joinType=[semi])
  EnumerableValues(tuples=[[{ 1, 2 }, { 3, null }, { 7369, null }, { 7499, 30 }, { null, 20 }, { null, 5 }]])
  EnumerableUnion(all=[true])
    EnumerableValues(tuples=[[{ 3, null }]])
    EnumerableValues(tuples=[[{ 7369, null }]])
    EnumerableValues(tuples=[[{ null, 20 }]])
    EnumerableValues(tuples=[[{ null, 5 }]])
    EnumerableValues(tuples=[[{ 1, 2 }, { 7499, 30 }]])
!plan

with
t1(a,y) as (select * from (values (1, 2), (3, 5),(7369,6),(7499,30),(2, 20),(3, 5)) as t1)
select *
from t1
where (t1.a,t1.y) in ((1, 2), (3, 3),(7369,3),(7499,30),(1, 20),(3, 5));

EnumerableHashJoin(condition=[AND(=($0, $2), =($1, $3))], joinType=[semi])
  EnumerableValues(tuples=[[{ 1, 2 }, { 3, 5 }, { 7369, 6 }, { 7499, 30 }, { 2, 20 }, { 3, 5 }]])
  EnumerableValues(tuples=[[{ 1, 2 }, { 3, 3 }, { 7369, 3 }, { 7499, 30 }, { 1, 20 }, { 3, 5 }]])
!plan