[clinic · EX-15] Make the dense leg earn its keep

[akash-coded]

Exercise clinic. One long-running thread per exercise. Ask here rather than opening a
new thread — the answers accumulate where the next person will look for them.

Exercise: EX-15 — Make the dense leg earn its keep · difficulty ⚫

What this exercise asks

Read the exercise first; this thread is for when you are stuck, not instead of it.

Three ways people get stuck on this one

1. Raising the dense weight until aggregate recall improves, without checking which classes it damaged.

2. Comparing the dense leg alone against the hybrid, rather than against the hybrid without it — the marginal contribution is the question.

3. Concluding the dense leg is useless when the encoder is the problem. ADR-0003 says the default encoder is deliberately weak.

How to ask here

Post the numbers you got, the config that produced them, and what you already tried.
A question with a measurement in it gets answered in one round trip; a question without one
takes three.

If you have finished it, post the write-up in Show and Tell with the
[solution · EX-15] prefix rather than here — this thread stays for people who are stuck.