It needs to be decided how to implement negative comparatives and superlatives (English “less”, “least”; Esperanto “malpli”, “malplej”). The obvious way is by means of adverbial particles, e.g. minder and minst, acting like detached prefixes.
A question for the adjectives is whether they should have their abstract nouns derived from them (e.g. ugly and ugliness) or be derived from their abstract nouns (e.g. beauty and beautiful). The simplest approach would be to always derive the abstract noun with the -heid-suffix but an alternative would be to follow the trends of the source languages. This would make Folkspraak more naturalistic at the cost of slightly reduced regularity.