The same problem Dolby Vision solves, on a different licence
HDR10 sends one set of numbers for a whole file. Both HDR10+ and Dolby Vision fix that by sending per-scene tone-mapping guidance instead. The difference is commercial rather than technical: HDR10+ was developed by Samsung and partners as an alternative with lower licensing costs, and it is administered by HDR10+ Technologies.
Graceful degradation is the design win
A Dolby Vision profile 5 stream is not playable as HDR10 without the Dolby decoder. HDR10+ is: strip the ST 2094-40 metadata and a conforming HDR10 file remains. That makes it cheaper to deliver, because there is no second stream and no fallback path to test.
Why this converter does not output it
Dynamic metadata has to be derived from a per-scene analysis of graded content. For a clip under 60 seconds with consistent lighting, the difference between static and dynamic metadata is usually not visible, and the tradeoff is a narrower set of players that will accept the file. Delivering plain HDR10 means the result plays on every HDR display without exception. See what the converter outputs.
Questions people ask
Do I need an HDR10+ television?
Only to see the dynamic metadata. Because the base layer is ordinary HDR10, any HDR display plays an HDR10+ file and simply ignores the extra data. That graceful fallback is the format's main practical advantage over Dolby Vision profile 5.
Is HDR10+ better than Dolby Vision?
Technically they solve the same problem with comparable results. The differences are commercial: HDR10+ has lower licensing costs and narrower device support, Dolby Vision has wider support and a licence fee. Neither is a clear win on picture alone.
Related: HDR10 vs Dolby Vision vs HLG.