End of the road for the BT-300 I'm afraid. Discontinued, and no more software development.
[Important Notice] Partial termination of Technical information and deadline of new Apps application - News - Technical Information - Moverio - Epson
Due to the discontinuation of the Moverio BT-300, BT-350, BT-2000, or BT-2200, as of Mar. 31st, 2021 (JST: Japan Standard time), Epson will no longer provide technical information for the BT-300, BT-350, BT-2000, or BT-2200.
tech.moverio.epson.com