The thing about words such as zwangsversteigern or voreinstellen is not that they are uncommon in the preterite, but that they are uncommon in any finite forms. Preterite forms such as *ich zwangsversteigerte or *ich stellte vorein are equally uncommon as present tense forms such as *ich zwangsversteigere or *ich stelle vorein. The only forms that are common are the non-finite forms: The infinitive zwangsversteigern/voreinstellen and the past participle zwangsversteigert/voreingestellt.
There are other words that are even more restricted, e.g. ungeboren – there is no infinitive *ungebären, let alone any finite forms such as *ich ungebäre or *ich ungebar. And this brings us closer to what might be the answer to the question: The reason why all these words cannot be used as full-fledged verbs is that they did not start out as verbs, but as some other word class.
The prefix un- is not verbal prefix, but a typical nominal prefix, used on adjectives (e.g. unschön, unvorsichtig) and substantives (e.g. Unglaube, Untier). The word ungeboren is not a verbal, but an adjectival composition. While gebären is undoubtedly a verb, the past participle is the verbal form that behaves like an adjective. So you start from a verb (gebären), transform it into an adjective (the past participle geboren), and then apply adjectival operations to it (adding the adjectival prefix un-): The result no longer is a verb, but a plain adjective.
The cases of zwangsversteigern and voreinstellen are similar. You start with a verb versteigern/einstellen, transform it into a substantive Versteigerung/Einstellung, apply some substantival operations Zwangsversteigerung/Voreinstellung, and then almost transform it back into a verb, but not all the way: While we can use the non-finite forms zwangsversteigern/voreinstellen and zwangsversteigert/voreingestellt, the finite forms cannot be used.