Experience with the discount protection of the HUK24?

Hello. I would like to allow a used car. (previous owner (my uncle) stays and I become a policyholder). As insurance I would like to take the HUK24. This costs me for the liability incl. protection letter 256€ in the year in the SF13. With additional discount protection (1 liability damage in the calendar year without any increase) I would pay 290€. Without discount protection I would pay in the future in case of damage 330€ or 39€ (with discount protection). of course, it is difficult to answer, the extra charge for protection is not particularly large, nor the one after the reclassification. I am more interested in your experiences, how the HUK24 exploits the customer retention measure after a damage case. Since I can not take over the SF class with me into another insurance, the possibility is obvious, to increase the contributions cheerfully. Just that happened to me with the DaDirekt: My previous car cost last year 530€ for SF12 and type class 18 and this year then 763€ for SF13 and type class 19. Therefore I tend to leave the discount protection away…or is the behaviour of DaDirekt rather unusual and not transferable to other (serious) companies? P.s. I would like to have the previous car registered for a short transitional period. Is the procedure correct, the DA direct by fax to inform that the insured car runs from 31.03. as a second car and I confirm + a modified invoice please? Thank you Wolf