Sometimes I face verb + 보있다 construction.
E.g. 바라보있다, 들어보있다. How this construction changes the verb meanings?
북한어 north-korean chose a vowel "l" than "ㅏ", compared to 남한어 south-korean, sometimes.
북한어 (남한어) : 그러니끼 (그러니까 thus), 수집다(수줍다 be shy), 부시다(부수다 break), 내놓이다(내놓아 지다 be shown), 엮이다(엮어 지다 be involved)
Long ago, gag man followed north-korean speaking for a satire or joy. In my thought, it is an easy technic. For instance, 내레 그러니끼 ... 그렇습니끼 ? (I thus ... is it true ?). That is, when we change ㅏ into ㅣ, it sounds like north-korean.
In case of 보았다, I do not know a north-korean of it (I do not know whether it is an influence of north), and exact origin. At any rate, in the internet, many people use 보있다. Maybe we can not see it 10 years ago. In my thought, 보있다 is more cute so that it represents an intimacy or a charm in internet.
I'm a Korean speaker from South and I've never heard or seen
보있다 used as verb.
At first I thought it's probably a misspelled word of
보았다, but if that's not the case, I guess it could be
Those all make sense and mean the same.
뵀다 would be used when people try out something unusual. If there is a difference between those two, it's that
뵀다 feels much more informal and non-standard than
The meaning of 보았다 itself is for the past term of "see" or "보다". but (verb)+보았다 is most similar to "I have (verb)."