I have a bridge app unrelated to bridgebase and it literally wouldn't let me open a trash 4-count with 3♥ the other day. Something like Kx Jxxxxxx xx xx :P 3NT is probably an OK bid to have in the system here but IMO there needs to be a distinction between 19-22 counts which shouldn't overcall 3NT, and 23+ which could. Given that, 4NT would actually be too light of a bid.