Probably best to keep the same syntax everywhere.

Should express the idea is the maximal length, not the properties count.

What about something like $propertyMaxLength?

To avoid such a long line, we can split it by column:

$send[] = '| Property' . str_repeat(' ', $maxProp - 8)
        .' | ' . str_repeat(' ', $maxValue) . ' |';

Method names use camel case e.g. makeId

Ah yes thanks to thing about those ones too!

Encoding for URL parts is different: you can use https://www.php.net/manual/en/function.urlencode.php

For example we need to escape # ? & / but we don't need to escape <>

Encoded twice, once here, once afterwards.

As the URL part should be encoded with urlencode() we can just discard that one

Ah by the way, you've min() and max() in a lot of languages: $propertyMaxLength = min($propertyMaxLength, 8);