Ugly conditional statement needs logical negation- HELP!

It’s the logical negation I not 100% on. I broke it down below. Please weigh in whether I am right or wrong.

The statement:
“People tend not to understand the purpose of restrictions unless they participate in the formulation.”

It diagrams like so:
~participate formulation-> ~understand purpose
understand purpose-> participate formulation

“If…then” rewording:
If people understand the purpose of restrictions, then they participated in their formation.

Logical negation confusion… here’s my best take on it:
When people understand the purpose of restrictions, they did not necessarily participate in their formation.

Part of me wants to reword it to:
People do not necessarily understand the purpose of restrictions, even when participate in their formation.

Please help!

“People tend not to understand the purpose of restrictions unless they participate in the formulation.”

understand purpose of restrictions —> participate in formulation of those restrictions
UPR → PFR

Negation:
UPR & ~PFR
People can understand the purpose of restrictions even if they do not participate in the formulation.

A good thing to remember, the negation of a conditional is never another conditional statement, it generally can be phrased most easily with “even if”.

To be fair, that negation is already possible with the original statement because of the word “tend”.

This is fair.

People tend to understand the purpose of restrictions even if they do not participate in the formulation.