How many steps should a sequence have?

I've been setting up an email campaign this past month for my company and I have some questions about optimally how many emails should you send per lead

We're sending 10-15 emails a day from one domain and one email.

Warmed up, deliverability is good, 5.7% reply rate.

We're using Apollo to search for leads that fit our ICP that is pretty specific, we send that to Clay to enrich them and we use Skyp.ai for the warmup and the scheduling, customization.

We're only doing a 3 step sequence:

Email 1 -> 2 days -> Email 2 -> 5 days -> Email 3. We're only sending it on Tue-Wed.

About 90% of our replies come from Email 1 and 2, is it worth it to add more steps to the sequence? Is 5 days too late to send a followup? Is it worth it to send more?

Would love some opinions, I'd like to A/B test some different approaches but I'm asking for some guidelines or what works for you guys to try out.