Travel book at 100% private use

Hello dear community, despite the danger that my question is not particularly clever, I would like to ask you. The following facts: My employer offers a company car model where the travel book method is mandatory. I would like to determine for myself the worst case. I as an employer have to pay a usage fee of 300 € net for the leasing rate. If we now assume annual costs of 1000€ and I would like to drive 100% private like in the case with the Fah can I get away worse with the travel book than with the 1% method or do I pay a maximum of 1%? Should I pay a maximum of 1% for a 100 percent private use then the bill for a BLP of 50 000€ would look as follows: 1%* 50 000 * 12 months = 600€ – 3600 user fee= 240€ = No further effects (first place of business left out) Is this so far correct? Thank you in advance and best regards Nima