[brudgers]

<answer based on generic startup model>

>The consulting wouldn't affect my main job

The higher your level of responsibility, the less likely it is to be the case.

However, the problem I see is that even if you get the blessing to consult from the startup founders, it is likely to fall outside of the company culture - there is a high probability that the consulting will necessitate a more 9-5 mentality than is appropriate for a person with substantial stock options (assuming the stock options are substantial enough that it doesn't take a billion dollar valuation to allow you the option to take up full time investing).

In the end, the side work is just too likely to be seen as a lack of commitment in an environment where others have forgone salary for the sake of the enterprise.

In other words, even if consulting doesn't affect your work, there will always be a reasonable suspicion that it does.