Embedded BLE / IMU Sensor Consultant Needed for Smart Punching Bag Product

We are developing a smart sensor module for a physical punching product. The product is a spring/reflex-style punching bag. Users punch the ball/head, the spring/rod rebounds, and we want to mount a smart sensor module on the rod/collar area to detect punches and estimate punch intensity. We already have the mobile app side handled. We are looking for a hardware/embedded systems consultant to help us define the correct sensor architecture and technical requirements before we speak to electronics ODM factories. We are not looking for exact professional boxing force measurement. We need a consistent, fun, consumer-friendly Power Score that increases when the user punches harder. The main challenge is that the sensor will detect the punch impact, but also spring rebound and vibration. We need help defining how to filter this properly so the device counts real punches and does not count rebound movement as extra punches. What We Need Help With We need someone who can advise on: Best sensor type for this use case: high-G accelerometer, IMU, piezo, vibration sensor, etc. Recommended G-range, likely ±200g to ±400g Recommended sampling rate Best mounting position on the spring/rod/collar How to avoid counting rebound/vibration as extra punches Punch-event detection logic Debounce/cooldown filtering False-positive prevention Fast combo punch detection BLE module requirements Firmware requirements What data should be sent from the module to our app Whether raw data should be processed on-device or inside the app Battery/charging considerations What to ask electronics ODM factories How to review ODM/factory replies and spot red flags Important Context This is not a glove/wrist tracker. The sensor will be mounted on the punching product itself, likely around the rod/collar area. The product moves and rebounds after impact, so the algorithm needs to detect the real punch and ignore rebound/vibration. We do not need someone to build the whole product immediately. First, we need technical guidance so we can brief ODM factories correctly and avoid choosing the wrong sensor/module.