no, although it could probably be added pretty easily to the get endpoint https://github.com/hzrd149/blossom/blob/master/Server.md#get-sha256---get-blob

Both @hzrd149 's and Stu's implementations forward GET requests (302 Found) to external blob storage services, i.e. the request is served by those services that DO support range requests. I have tried to implement range requests with my cloudflare worker based solution and have still some bugs/issues. Downloads (GET) with ranges are covered well by the HTTP spec. IMHO it could make more sense to put a multipart upload API in the blossom spec to support large files.