The vast majority of setups are fine to normalize to origin; its only if you have applications or origin-side configurations that expect percent encoding (like certain legacy applications and some API gateways).
Thats why we took the decision to not do this globally for everyone, and instead have it only on for ‘what Cloudflare products see’ so that Firewall Rules, Page Rules, Workers, Transform Rules, et al all see a consistent input - regardless of the tricks malicious actors may use such as path traversal, encoding, etc.
If your origin doesnt need to receive encoded traffic then your fine to turn this on in both directions.