Please do. It would be a great project. Model rocket engines can’t be throttled so your ignition has to be perfect and your engines identical. If you do it please share the results with us.

Check out BPS.space who spent 7(?) years exploring exactly this!

Yes! I agree, a great series. But what about weekend projects? Looking at the Estes and other model rocket sites it looks like cluster rockets are already a thing.

Could you hold it back on the launch pad for a second to ensure all engines are lit up prior to lift off?

The C6-3 engines sold with this kit generate thrust for 1.6 seconds total.

https://estesrockets.com/product/001613-c6-3-engines/

I was the first in our group to launch a two-stage. Minimal motors for the first launch, it staged barely clear of the launch rail.

Not even the Shuttle tried that. If they didn't both light within a very narrow time window the whole thing would go boom on the pad.