I'd also argue that 72 is too low, especially when dealing with structures.
(This isn't a punched-card or even a git commit message title. My standard window is 176 columns.)
For example:
Reference {"inflate_via" => "pg","inflate_with" => {"with_age" => 1,"w...} did not pass type constraint "Dict[inflate_via=>Maybe[StrMatch[(?-xism:^(?:es|pg)$)]],inflate_with=>Maybe[HashRef],page_number=>PageNumberType,rows_per_page=>Int2_not_negative,search_criteria=>Ref,search_via=>Maybe[StrMatch[(?-xism:^(?:es|pg)$)]],sort_order=>Str]"
The truncation means the error message isn't helpful in identifying the actual cause.
It's a pity that Data::Dumper doesn't offer more control, such as limiting the length of individual values. I understand that Type::Tiny has to live with that.
Perhaps, in addition to raising the default (I'd suggest somewhere around 300..500), you'd consider making the ref dumping part of _dd pluggable so users can provide their own.