I've been using Tixati since I think 1.2x when it got Win7 support.

I've kept "upgrading" and have never really clean-installed.

I'm at about 1,600 Transfers in the "All" category I mostly keep them so I can easily tell what I've gotten in the past, just to keep things organized, I really like how Tixati warns me if the hash already exists and if I'd like to merge the trackers, I use this prompt as a warning to tell me that I'm grabbing a duplicate torrent, I've had to switch/upgrade HDDs a few times before since 1.2x so things are on the PC but not always in the Default Folder.

I've recently hit some major slowdowns browsing the list or opening from taskbar/minimizing it usually goes "Not Responding" for about 30-60secs getting a bit worried.

Two questions:
1) How can I backup the entire Transfer list so I can try a clean install of Tixati.
2) Is it just 2.23 or is it what I fear, some transfer limit.

Windows 10 Pro
16GB RAM
Default Folder is on a 4TB HDD, have run SMART and chkdsk scans, no issues with the drive.

Answer to question 1:  Check out Settings > Import / Export, it's the last page in the settings.  This works well.

Answer to question 2:  There is no transfer limit.  Some people have 10x the number of transfers, no problem.

I suspect this is your hard-drive / file system causing the slowdown.  There are some diagnostic tools in the Help menu (button at top-right of main window).  You might try looking at the File Operations Log and see if there are any delays in there while this problem is happening.  It has the time logged in there, so you can see if it was a file operation that started the delay.

Or maybe it is something else... is the CPU running hard while Tixati is hanging?  Or is your hard-drive working hard?

If you want to post some logs in here maybe one of the developers or mods can have a look.