Want trader input on DMA vs B Book/safety of funds/spreads etc

I would be interested to hear from any traders with views on b book vs DMA / safety of deposits (wallets).. spreads and market transparency.

I am not a broker nor work for a broker.. happy to provide my linked in profile if you pm me.

I am looking at regulatory aspects of the retail business and ways to make it more transparent and safe, and this needs input directly from trader experience ..

Want trader input on DMA vs B Book/safety of funds/spreads etc