I believe a regular, plainly defined pattern, helps Bush Verse immensely. The number of lines in a stanza of Bush Verse can be whatever the author chooses, but I prefer to keep to four, six or eight lines.
Long stanzas of verse, like long paragraphs in prose, tend to tire the reader. That tiny break between stanzas seems to refresh the reader’s mind and allows him/her to concentrate better on the new stanza.
Once you decide the number of lines in the stanza, stick to it. The only variations I make (and then only rarely) is the first stanza that may differ by way of an introduction, and the final one.
For example I might sometimes be working on an eight line stanza pattern and find I can say all that is left of any importance in four final lines. Usually, though, I keep the stanzas uniform throughout the poem.
Stanzas of five, seven or nine lines can be made to work well with one loose line of good metre, but not rhyming, to end each stanza.
Or this extra line can ryhyme with almost any other line if the author so desires, but it is better not to have rhymes too far apart as they lose impact. Again this extra line is something I do only rarely.
Apart from the number of lines per stanza, the number of syllables per line and stress order go to complete the pattern.
It is not necessary to have every line the same to make a good pattern. For example line one might have fourteen syllables beginning with an unstresssed syllable and line two eleven syllables beginning with a stressed syllable. But the rhyming lines should be the same.
In this case, assuming that your rhyming pattern is ABAB, lines one and three must be the same and lines two and four also identical.
Once you decide on these things, stick with it. It is disappointing to see a poem start off really well and change course mid-stream without reason.