Finnish impersonal verbs

I guess every language has many impersonal verbs for which only the 3rd person is used - a typical example could be sataa (“to rain”). 1st and 2nd person forms such as minä sadan, sinä sadat, minä sadoin are grammatically possible but illogical. Do you think you could develop the Module:fi-verb so that by adding a qualifier, the conjugation table would show only the 3rd person forms? For example, in case of sataa, the conjugation template could look like this:

{{fi-conj-kaivaa|sa|t|d|a|impersonal=1}}

If they are possible, then they should be shown because someone might occasionally use them. A sentence like "we rained down on them like hailstones" is perfectly valid in English and not at all illogical, just poetic. The same probably applies for Finnish?

@Hekaheka, CodeCat Sorry for commenting so late, but: it depends on attestation, doesn't it? Some verbs are probably used poetically outside of the third person, others aren't. For the ones that are truly impersonal, it should indeed be possible to suppress the invalid first- and second-person forms... compare regnen (used poetically in the first and second person) and fisseln (only used in the third person).