New update for July 2021. As of 15 June 2021, California has reopened. Mask wearing is now voluntary, but it's obviously still advised to be worn for your and other precautions since the pandemic and new strains (Delta variant) are still around and spreading.
The gym in South San Francisco (and I would imagine the other Bintang facilities) are open 100% now. No more reservations are required (there is a paid option if a group desires to guarantee themselves a court). Now, it is drop in and rates are higher than before. I believe it's $15 for drop in, play as long as you want, with no in/out privileges. I'm a lifetime member so I simply just scan my card. All members will have their memberships unfrozen automatically now - check Bintang's website for exact details.
So what does this mean? Essentially, it is just like before the pandemic. It's actually been busier than before (or seems that way), and every familiar face/regular player has returned with their groups. Every court is occupied. You will be hard pressed to sign up for courts on their computer if you come during peak hours on weeknights, so definitely come in (with your group) when the gym opens at 6pm, or later around 8.30/9pm when people start to leave. The gym closes at 10pm on weeknights. Weekends are similarly busy during the morning and day time. Again, check with the site, or call/email them for specific details on their hours.
Anyone coming in to play wearing masks, I will just say, you're gonna end up taking it off anyways (it gets really humid/sweaty), or don't bother coming to the gym if you are still concerned for your own health. It's just not practical and if you are sick/unwell, you should obviously wear a mask if you need to go outside (e.g. grocery shopping) or stay at home to recover. Nobody at the gym will be wearing masks while playing badminton. It's a strenuous sport, even if you are playing doubles.
Stay safe, stay healthy and happy shuttling!