Wider spread during market opening is normal. The spread is widest at the start of the trading session and then it should quickly shrink. Normally within minutes, the gap between the price sellers wants which is known as the “ask” price, and what buyers are offering - the “bid,” shrinks sharply and continues to narrow up until the end of the trading session. In my opinion the overall cost to trade is lower, and the risk of getting a bad trade is lower, if you wait 30 minutes after the market opens. However be aware that if you are trading with a market maker it could be that the current marker spread is manipulated and trading cost are included within the offered spread.

"When the market is dead" meaning the market is closed. So, it is not possible to increase the spreads.