Unusual Penalty Accepted/Declined Situation

[NJOfficial]

Here is an unusual situation I encountered in an 8th grade game a few years ago. I'd love to hear some input.

3rd and 30 from A's 40 yard line. Quarterback A7 drops back and throws a forward pass to A85. B20 commits defensive pass interference on A85, but A85 catches the pass anyway and is downed at B's 35 yard line, 5 yards short of the line to gain.

Accepting the 15-yard DPI penalty would place the ball at B's 45 yard line with an automatic first down. Declining the penalty would result in 4th and 5 from B's 35 yard line.

A's coach wishes to decline the 15-yard distance penalty but take the automatic first down, thus resulting in 1st and 10 from B's 35 yard line. Is this acceptable?