Re: Errors and Omissions Claim After 3 Years Question.
This is a query that often comes up with financial lines insurance.
The purpose of carrying coverage in the first place is to ensure that you're protected when you need it. If the circumstances that you describe, satisfy the definition of "claim or circumstance which may lead to a claim", according to your policy wording (which I presume is written on a claims-made basis), your first priority should really be notifying your insurer. Once you have notified them and they have acknowledged that it falls within their scope of coverage, it places you in a much better position to make decisions moving forward.
While I personally always encourage continuity of coverage - that is, maintaining coverage with your incumbent insurer - if you're really concerned about your premium it wouldn't be such a bad idea to get on the front foot and source alternative quotations in the lead up to your renewal. Then, at the very least, you will have options should your current provider significantly raise their prices or not offer coverage for the next period.
Of course, you will need to disclose all claims and circumstances that you are aware of during the quoting process, so these instances will not be covered by any new policy. As a final note, if you are thinking about transferring insurers, I suggest giving the holding provider every chance to maintain the account. Insurance coverage, in my opinion, really is a long-term game, and you get the best results when you are as transparent as possible.