Max Clicks vs tCPA for a COD nutraceutical campaign?

Hey everyone, I’d really appreciate some advice from people experienced with Google Ads and Smart Bidding.

I’m running a Google Search campaign for a nutraceutical COD offer in a European country. The payout is around $40 per confirmed sale.

The funnel works like this: the user searches for the product, lands on my page and fills out a form. The advertiser’s call center then contacts the lead and tries to close the sale. I only get paid when the order is confirmed.

The campaign has been running for about two weeks. I initially used Maximize Clicks with a €0.80 max CPC.

The important part is the conversion tracking:

Initially, Google was counting both the lead submission and the confirmed sale as conversions. The lead fires when the user submits the form, and then I send the confirmed sale back to Google as an offline conversion once the advertiser confirms the order.

I’ve now changed the setup so that lead is a secondary conversion, while the confirmed sale is the primary conversion, because the lead itself has no real value to me. My actual goal is profitable confirmed sales.

Right now, the campaign has a €60/day budget, but Google says it is limited by bid strategy and is recommending a tCPA of around €14.50.

My concern is that Google may still be basing that recommendation largely on the historical lead conversions rather than confirmed sales, since the campaign previously counted both events as conversions.

The campaign is very bottom-of-funnel. I’m targeting exact match keywords around the product name, such as:

[product name]

[product name + buy]

[product name + price]

There are roughly 150 searches per day for the product name and related high-intent searches.

My goal is simple: profitability. With a $40 payout, I’d be happy if I could consistently acquire a confirmed sale for around $18–20 or less.

So my questions are:

Would switching from Maximize Clicks to tCPA make sense for this type of COD campaign?

If Google is currently recommending €14.50 tCPA based on historical conversions that included leads, should I ignore that recommendation until I have more confirmed-sale data?

Would Smart Bidding actually be able to optimize effectively when the real conversion is an offline confirmed sale from the call center?

Would you start with Maximize Conversions first and then move to tCPA once enough confirmed sales are recorded?

With only ~150 daily searches and exact-match, is there enough volume for Smart Bidding to work properly?

I’m mainly looking for advice on the best bidding strategy when the lead is easy to generate but the actual conversion happens later through a call center.

Any advice or experience with a similar COD setup would be really appreciated.