Does anyone have any case law or experience dealing with the issue of punishment witnesses and the Rule? I've had several defense attorneys lately argue that their punishment witnesses can be in the courtroom during guilt/innocence and I havent been able to find anything on point other than the statute.

Check out Lester v. State (2011Tex App Lexis 315), it deals briefly with the matter. In that case a state witness was called only to ID his dead wife as the victim and was allowed to remain despite being available in punishment. Tthe court said due to the limited nature of his testimony it was ok, but suggested exclusion would be appropriate if they had more substantial information. It's unpublished but hope it helps.

It certainly seems arguable that the testimony of a character witness might be materially affected by hearing testimony about the offense. Plus, there is no mention of these witnesses being excluded from the "rule" in Rule 614, and thus the "shall order" provision should mean just that. 882 S.W.2d at 848. But, a defense witness who learns first-hand the details of the crime is probably more readily cross-examined about his opinion of the defendant and could conceivably even change his mind about the defendant's "better" qualities, so I am not sure how strongly to oppose the request in any given case.

I would oppose it strongly. The character witnesses may or may not be aware of some of the issues that may be discussed and of some of the alternate theories thrown out by the defense. Keeping them out of the courtroom prevents them from developing any form of corroborating testimony from what they just heard.