This is how I have mine set up
I have automatic management turned on
Preferences-> sending books to device
1. PRS-t1 plugin
preferences->plugins->Sony PRST1
Click customize plugin
I have every checkbox unchecked except for epub
I have {author_sort}/{title} - {authors} in Save Template box
I have author_sort in comma seperated list... box
This is not necessarily what you will end up using as most people have series collections as well, but I keep a lot of books on my device
2.Sorting by series
Polarpenquin's probably right on this one
sony_collection_sorting_rules = [(['series'], 'series_index')]
Mine is
sony_collection_sorting_rules = [(['author_sort'], 'series_index')] which is strange. Seems to work but may try Polarpenquin's
3. Plugboard (from Jackie_W)
Preferences->metadata plugboard
Format
I have any format but probably should be specific and choose EPUB etc.
Device
I have any device but probably should be specific and choose PRST1
Source template
{author_sort}{series:| - | }{series_index:0>2s}
Destination Field
authors
(this appends series name and number to author field on T1 does not affect library and looks good on T1)
This works great for me. I would like to have series collections as well, but I have currently 193 authors (books, anthologies)on T1 many with more than one series it is too cumbersome to page through.
For the plugboard to work you have to resend the books
For the plugin to work you may have to reconvert books to embed series metadata. I always do if I change the series field but may work without.
Warning: You may lose your current collections when it makes new ones. However when you get it set up the way you like it, it will work flawlessly.
I would advise one step at a time and testing

Write down old settings as you go if you can.
This thread has post by Jackie_W that gives plugboard instructions and picture.
I used the device_db for PRS 600 and PRS 350 but had problems with T1 so I changed device_db to any device.
https://www.mobileread.com/forums/sho...ight=device_db
Helen