If you are looking for Best OST to PST converter tool then you should try Dux OST to PST software. It is capable to recover .OST to .PST, and it also convert OST to PST file. With multiple format like as:- EML, MSG, EMLX, DOC. TXT, MBOX and outlook profile. as well as it also break heavy size of recovered PST file upto 5GB and work all PST file as:- 97, 98, 2000, 2003, 2007, 2010, 2013, 2016 and 2019.
For more info you can search on Google - "Dux OST to PST Converter” OR https://www.duxdatarecovery.com/ost-to-pst-recovery.php