Can I still make a claim if I waited to see how the business performed before deciding to sue?

Possibly, but waiting carries real risk. Both the negotiated survival period for an indemnity claim and Ontario's general limitation law generally run from when the problem was discovered or reasonably ought to have been — not from when you personally decided to act on it. Watching the business perform before deciding to sue doesn't pause either clock; it just means time keeps running in the background while you wait.

Delay can also feed into a separate argument that your own conduct suggested acceptance of the situation, though courts are generally reluctant to treat mere patience alone as a waiver of a legitimate claim. The bigger practical risk is simply running out the clock on a survival period or limitation deadline while you were still deciding what to do. If you've already discovered a potential problem, get it assessed promptly, even if you haven't decided whether you actually want to pursue it yet — that assessment doesn't commit you to suing, but it protects your options.