If the company was struck off for not filing accounts then that is purely on them, not the BSPL. Assets of a struck of company transfer to The Crown, and would have to be bought back by the new Ltd Co. Normal day to day operating of the assets as an individual or as the sole director and sole shareholder of a limited company is no different (unless the company gets stuck off), but a Ltd Co pays less tax, especially if the individual pays higher rate tax. If the Ltd Co had any assets that were required for speedway to run (track, licence, riders, visas) then the club could not run whilst The Crown owned the assets, which again is nothing to do with BSPL. Involvement of another promotion (through sponsorship) is likely related to the quickest way to sort visas as presumably it's easier and quicker for an established company to obtain them than a new one.
Whatever the cause of the issues, it's good to see the Comets back on track (and hopefully filing accounts on time!)