From a market/capitalism point of view, there will always be a conflict of interest. The US government would be biased in awarding contracts to companies it owns even if competitors offers are better.
- It is being imposed at least semi arbitrarily, which is obviously a massive corruption risk. You point out part of the risk, but there are other parts too.
- This administration both ran and executed on corporate tax cuts. Backdoor re-introducing a very similar thing does not give confidence.
If the policy was to take a stake in the S&P 500 or something, and it was not implemented by an administration that is otherwise leaning into corporate tax cuts, I would be basically fine with it.