Newer versions of TCPDF not deleting temporary image files in cache

I have a Drupal 7 site that is using Views PDF, with TCPDF (Version 6.2.26) installed as a library. This site generates PDF versions of a specific view. This feature was working fine until an updated version of TCPDF was installed, at which point the cache (sites/default/files/views_pdf_cache/) started to fill with temporary image files. Every time the view ran, new files were created, but never removed. However, no PHP errors were generated to indicate why these files were being left behind.

Based on information in this ticket for Views PDF (https://www.drupal.org/project/tcpdf/issues/2700117) I reverted to an older version of TCPDF until the issue resolved. By trial and error, I discovered that whatever is causing the issue was introduced between versions 6.0.099 and 6.1.0. Diffing these versions shows a number of changes related to the destruction of cache files.

As you can see from that ticket, the Views PDF devs ultimately referred the issue back to TCPDF and closed the ticket, which is why I'm posting this ticket here. My site is currently able to create PDFs with no issues using version 6.0.099, but obviously this is not a long-term solution. I'm running the latest versions of Drupal 7 (Core: 7.66) with PDF Views (7.x-1.7).