With getting breath/blood tested in your house, it would be a grey area, They are allowed to breath test you but it would be frowned upon by the courts if they made any delay in obtaining the reading.
With all due respect you need to state facts because what you've said is not correct at all, there are no grey areas. If you read back through the other posts you'll see there is very clear criteria that must be met before the police have the legal authority to enter and remain on your property to carry out a breath test (in this case you have no say as to whether you want them there or not), while the other posts centre on what they can/can't do if they're not in fresh pursuit.
As far as your comment about being frowned upon by the court for delays in obtaining a reading, well I don't know where you've got that from because a blood test is not conducted in someone's house, and once they blow into the device at the house it's either a 'pass' or 'fail general' or 'fail youth' result which is near instantaneous and if they fail they are immediately required to accompany the officer to a police station, so it's next to impossible for any delays to occur in obtaining a reading.
In a forum like this which is read by many people, who know many other people, who also know other people, and so on, people need to be careful about what they post on subjects like this - it's how old wives tales start and spread around!!! Just like the one that says a police officer can't give you a ticket if they're not wearing their hat......... hahaha