Issue Summary:

Events with big payloads that coincidentally also have lots of characters to be escaped (such as stringified JSON), are not getting through due to exceeding size limits because the characters are escaped again further down the line.

Steps to Reproduce

1. Step 1: Create an app event with a big payload (around 200kB), with lots of signs that should be escaped (such as stringified JSON).
2. Step 2: Send the event

Expected Results

Async Event should be delivered successfully or not accepted at all.

Actual Results

The Async Event is accepted but never delivered.

Workaround

Send an object as Async Event payload instead of a stringified JSON.