Question regarding continuous media

Hi,

In my free time, I am currently working on a small thermal printer 
driver using the PAPPL lib.
I defined a media called: continuous-short_bdl_58x0mm (5.1.3 5101.1-2023)
but when sending a job with e.g. 58x99 it fails validating the media size

if (op != IPP_OP_CREATE_JOB && (supported = ippFindAttribute(client->printer->attrs,"document-format-supported", IPP_TAG_MIMETYPE)) != NULL && !ippContainsString(supported, format))
{
   papplClientRespondIPPUnsupported(client, attr);
   valid =false;
}

job-ipp.c:540


Get-Printer-Attributes response:   media-size-supported 1setOf 
collection {x-dimension=5800 y-dimension=0},{x-dimension=5100 
y-dimension=2600},{x-dimension=3000 y-dimension=2000},{x-dimension=4000 
y-dimension=4000},{x-dimension=4000 y-dimension=5000},{x-dimension=4000 
y-dimension=6000},{x-dimension=5000 y-dimension=3000},{x-dimension=6000 
y-dimension=6000}
Get-Printer-Attributes response:   media-source-supported 1setOf keyword 
main-roll,auto
Get-Printer-Attributes response:   media-supported 1setOf keyword 
continuous-short_bdl_58x0mm,labels_bde_51x26mm,labels_bde_30x20mm,labels_bde_40x40mm,labels_bde_40x50mm,labels_bde_40x60mm,labels_bde_50x30mm,labels_bde_60x60mm
...
Validate-Job response:   status-message textWithoutLanguage Unsupported 
media-col collection value.
Validate-Job response: unsupported-attributes-tag
Validate-Job response:   media-col collection 
{media-size={x-dimension=5800 y-dimension=9999} media-bottom-margin=0 
media-left-margin=0 media-right-margin=0 media-top-margin=0 
media-source=main-roll media-type=continuous-short}


so I am puzzling over, if I am on the wrong path, or how to do it right?

Regards
Armin