This is quite a nice application, but perhaps I am not alone here:
Sometimes I want a belt to contain 2 of module A for every 3 of module B or something similar. One can hack this together, but here's a proposal for how one could achieve this more cleanly:

Have a limiter gate block that can be linked with a group of other limiter blocks. Each one is configured with a number. They will let that many items though and then block, until all limiter gates in the group have become blocking, in which case they'll reset

While I would also love throughput limiters as described in https://modulus-feedback-and-suggestions.featureupvote.com/suggestions/704208/conveyor-limiter, these gate blocks would keep the correct ratios even if eg. the module A factory fails to output at its usual speed.