Work Visa and Work Permit Exemption for German citizen in Turkey for the duration of one week

I am a little bit unclear about some specific visa requirements for a German citizen visiting Turkey on behalf of a German employer providing services to a Turkish customer for the duration of one week.

My employer sells complex electronic systems all over the world. Specifically, in Turkey, via a Turkish partner, who buy systems and services from us and re-sell them to the local end-customer. In November, I am scheduled to travel to Turkey for one week for the purpose of configuring such a system.

It is my understanding that I cannot use the visa-free program, since this is not a tourist or commerce activity. I will need a Work Visa. It seems that I qualify for a Work Permit Exemption ("For the purpose of installation,maintenance and repair of machinery and equipment imported to Turkey, providing training for their utilization […]").

Is that understanding correct?

In that case, I will have to apply for a Work Visa at my local consulate, and for a Work Permit Exemption at the Ministry of Labor (which I can do through the local consulate at the same time as the visa application). As supporting documents, I will need:

• Biometric photo
• Hotel booking
• Flight reservation
• Supporting documents from employer, including at least:
  • purpose of visit
  • date of visit
  • place of work

I could not find any specific requirements for proof-of-funds, nor any vaccination requirements.

Is that correct? Did I overlook something important (for example, might I actually still qualify for a visa-free entry)?

If we want to get really technical, then our partner received training on how to configure such a system. So, they should be able to perform the configuration by themselves, in which case I would only be advising them, which then would qualify as a meeting or consultation and allow me visa-free entry. However, I do fear that this distinction might be lost on an immigration officer at the airport, and so I do not want to pursue this line of reasoning.