horrible advice. there's no where on earth this will be accepted and defeats the OP's requirement of being employed WHILE validating an idea. 1. would get you sued
That’s not necessarily true. Many founders end up selling products or services to the companies they previously worked for. I know of more than one person who left a previous company to pursue something that started as a side-project that many of us were aware of long before their departure and wished them well. There are plenty of places where if you’re getting your work done people are actually reasonable and nice, at least my experience with startups has seemed this way.
Many founders seem like a doubtful choice of words. There are even more founders that have landed themselves in legal waters because they just assumed their employer would be understanding like them.
High risk of failure, high risk of litigation if we took your questionable anecdotes without any proof at face value and suggest to OP to do the same.
This is especially true for large companies with people who are hired to handle litigation and IP risk management.
If the OP is a valuable employee and the company's options are to lose them or let them do something the company doesn't care about there's no harm asking at all. Don't ask, don't get.
How would discussing your contract with your employer get you sued?
1. Discuss with your employer to get the clause revised
2. Validate anyway
3. Change jobs to one without the clause
4. Give up on the idea
If you speak to your employer and they don't budge, make clear it's a quitting matter, unless you'd rather just forget the idea.