@Lurch There are a few different types of envelope nodes you can use in scriptnode. Just use one of these, synchronize it's triggering time with your recording time, and use it to modulate a gain node. That way you can create a window to smooth out the edges of your audio buffer.
Something like this perhaps:
HiseSnippet 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2fJ2aGhlhjrYQXkwxZPhk0fTkJvV4nkA4Tv24fotoJ+rgUjP4+BhPIegXokgXokUohsUpsIyPSBwc2FLAbWkC9NS7kDI+rxX3MfX3MfpPX6SKGqLCf+JmSClBtlFHHY4q+M4Wig2fFCuAMbUBcKGqLDEE4ftJPVYxXt9dwZQg7xMqLFdC5L7FzMqRna4N0RDREwa+yUj0nmMI283EgMJxsMmg2fACuAC4pD5hJImWjBO2tJJPxvpxJWeNulLYCaxjMroZUBcK40MWAaxEcitKupJ2D22bVRCRrjFjpTA1J28MW2TxTgK.iTfZ3dOmv.WtBP6Ul8B8Kydg9ipox.vkhUltljgLW7UyTg28hl1EH113f26huyocrZ56cPxOMzzu4o2KpDXsvM4eHT1h977xBmN7uRHcraYePylYeUizQkx1Q0x1QTY6nVY6ndY6Htrcz3p6H8G0gjeeeneU2ED1Zm0i+5DWa89echmTfj76TX7+9PQ+pN2uDWx48+odsczuxqSP+qTII5WK7ENN8eiyh+FH+egUQ1Iq