[FEA][C++ API] Check for hidden H2D copies in ACE path

[HowardHuang1]

Hidden H2D copies in ACE path were previously added to preserve / mirror upstream ACE behavior
Need to re-evaluate because this goes against our contract of never hiding memory allocation from user
#1846 (comment)
#1846 (comment)

[cjnolet]

Need to re-evaluate because this goes against our contract of never hiding memory allocation from user

I'm not sure I agree with this- we are not "never hiding memory allocation from user".

If that were the case, we would expose every temporary workspace allocation directly to the user. What we are doing is making an explicit contract for long-running allocations so that the user has full control over them. Let's make sure we clearly distinguish the two when we communicate changes like this. It's not obvious to me what the description in this issue is implying.