I am not a follower of VLT either, but their track record has some spots, so a bit skeptical of the acquisition. Damstra's management, of course, is far better informed than the average investor, so you have to afford them some rope. I think the arbitrage gap reflects the market's skepticism as well, so it is persists stubbornly.
The scheme of arrangement still has good odds to go through though, so it may be worth a small punt to acquire DTC shares cheaper via VLT, provided you appreciate that there is a non-zero chance the deal falls through and can live with that.