Testing C++ code and IsBadWritePtr

I am currently writing some basic tests for some functions of my C++ code (it is a game engine that I am writing mostly for educational purposes). One of the features I want to test is the memory allocation code. The tests currently consist of a function that runs every startup if the code is in debug mode. This forces me to always test the code when I am debugging.

To test my memory allocation code my instinct is to do something like this:

int* test = MemoryManager::AllocateMemory<int>();
assert(!IsBadWritePtr(test, sizeof(int)), "Memory allocation test failed: allocate");

MemoryManager::FreeMemory(test);
assert(IsBadWritePtr(test, sizeof(int)), "Memory free test failed: free");

This code is working fine, but all the resources I can find say not to use the IsBadWritePtr function (this is a WinAPI function for those unfamiliar). Is the use of this function OK in this case? The three main warnings against using it I found were:

This might cause issues with guard pages

This isn't an issue as the memory allocation code is right there and I know I am not allocating a guard page.

It's better to fail earlier

This isn't a consideration as I am literally using it to fail as early as possible.

It isn't thread safe

The test code is executed right at the beginning of execution, long before any other threads exist. It also acts on memory to which no other pointers are created, and therefore could not exist in other threads.

So basically I want to know if the use of this function is a good idea in this case, and if there is anything I am missing about the function. I am also aware that something that points to the wrong place will still pass this test, but it at least detects most memory allocation errors, right (what are the chances I get a pointer to valid memory if the allocation fails?)