Solving the "Running Kids" noise complaint in an apartment—Acoustic Floor Plan check?

Hi everyone, I’m looking for a sanity check on a hallway floor upgrade. I’ve had a few noise complaints from the neighbor downstairs regarding "thumping" from kids running in the 8m corridor. I need a solution that balances soundproofing, allergy needs, and door clearance.

Current Plan:

1. The Floor: Replacing old lino with Moduleo LayRed (rigid core LVT with built-in 21dB acoustic backing). I'm told not to use extra underlay under the LVT to avoid clicking joint failure.

2. The Buffer: Adding a 7mm SpringBond (PET felt) underlay on top of the LVT. Choosing this over rubber crumb because it's odorless/Allergy UK approved.

3. The Surface: An 8m custom Runrug (Easy-clean polypropylene). The Math: LayRed (6mm) + SpringBond (7mm) + Rug (5mm) = 18mm total stack. . Questions: • Has anyone used SpringBond under a runner? Is it stable enough for kids "sprinting" if I use LVT-safe double-sided tape?

• Is there a better 6-8mm impact underlay for LVT that won't cause yellowing/plasticizer migration?

• For the neighbor, is this ~25dB+ total reduction enough to kill the "thumping"?