If you want just forbid marking files with bitrate 320 and above, you can use this automarkin script (you may want change priority too, it's very easy see if):
/*
Author: Similarity Team
Version: 1.0
Description:
Simple auto-mark dialog analog
For speedup before launch analyze all files ("Analyze all" context menu)
*/
// unmark all files
results.audio.unmark();
// simple mark by lower bitrate
var dups = results.audio.dups;
for (var idx = 0; idx < dups.length; ++idx) {
let item1 = dups[idx].item1;
let item2 = dups[idx].item2;
// skip counter-pair (1-2 and 2-1), process pair only once
if (item1.path > item2.path) continue;
// don't allow mark files with bitrate > 320
mark1 = item1.analysis.bitrate > 320000 ? false : true;
mark2 = item2.analysis.bitrate > 320000 ? false : true;
// first priority
if (item1.analysis.rating > item2.analysis.rating)
{ item2.marked = mark2; continue; }
if (item1.analysis.rating < item2.analysis.rating)
{ item1.marked = mark1; continue; }
// second priority
if (item1.analysis.duration > item2.analysis.duration)
{ item2.marked = mark2; continue; }
if (item1.analysis.duration < item2.analysis.duration)
{ item1.marked = mark1; continue; }
// 3rd priority
if (item1.analysis.maxFreq > item2.analysis.maxFreq)
{ item2.marked = mark2; continue; }
if (item1.analysis.maxFreq < item2.analysis.maxFreq)
{ item1.marked = mark1; continue; }
// 4th priority
if (item1.analysis.clicks > item2.analysis.clicks)
{ item2.marked = mark2; continue; }
if (item1.analysis.clicks < item2.analysis.clicks)
{ item1.marked = mark1; continue; }
// 5th priority
if (item1.analysis.clips > item2.analysis.clips)
{ item2.marked = mark2; continue; }
if (item1.analysis.clips < item2.analysis.clips)
{ item1.marked = mark1; continue; }
}