local our $limit = 10;
/($re)(?(?{ length($^N) > $limit })(?!))/
[download]

It will even backtrack until the limit isn't exceeded unless you do something like

/((?>$re))(?(?{ length($^N) > $limit })(?!))/
[download]

The features aren't nearly as experimental as implied. After all, they survived three major version (5.6, 5.8 and 5.10)! $^N requires 5.8, but you can use $1 if you want compatibility with 5.6.

Update: Oops, forgot that this needed to be for split. Well, the comment on the experimental features still applies.