I think the 45 minutes limit mostly comes from Google's requirement, and data from other provider (e.g. tracking protection) may not need such frequent updates.

It's part of the Safe Browsing protocol (which we use for TP and will start to use for Shumway ads soon): https://developers.google.com/safe-browsing/developers_guide_v2#LookupsAgeOfDataUsage Other providers are likely to want something similar to ensure that stale data is never a problem even if the server becomes unavailable. Unless we have a good reason for wanting to make this customizable, I think we should things simple and stick to the existing limit since it comes in in a few places in the code (e.g. exponential backoff algorithm) and would be easy to get wrong. Marking as WONTFIX for now, but we can re-consider later if we have a use case that warrants the extra complexity.