The larger problem is that the IP assignment clauses are way too broad in the US. When I worked at Microsoft I had one that theoretically covered everything I wrote regardless of when, where, or on what devices. As an hourly worker, though, Microsoft was never going to exercise that due to overtime issues.

I rechecked my contract and under the terms of the contract, if it is specific to my work at my employer, they could claim it, but frankly we prefer to release everything that isn't specific to our industry open source anyway, so.....