Hi Mate,
0.8 degrees of castor is well within tolerances, as long as camber and toe are correct then you wont have any issues. Our track cars will often run 3-5 degrees of castor depending on track type and/or conditions with no issues.
Keep an eye on tyre wear, castor shouldnt affect it greatly, if at all but on accident damaged cars it can show up any other issues which may net have been first diagnosed.
Hope this helps,
PDT