From 6-9 mos board - CIO for crawling LOs?

Hi, Ladies!  I'm visiting from 6-9 months with a question - Anyone let their crawling LOs CIO?

My LOs will be 8 months old in just a few days and I am STILL BFing/rocking them to sleep.  I thought it was exhausting when I did this with just ONE baby for the first SIX months! I'm so ready for this to stop. Fiona consistently STTN and I'd say Anna does about 5 out of 7 days of the week. When she wakes up, it's usually begtween midnight and 2 a.m. and she's never hungry, just wants to snuggle and go back to sleep.  One of my concerns is, they are both crawling.  Anna just on her belly and Fiona on all fours.  When we let DD1 CIO, she was about 6.5 months old and she wasn't crawling yet, just rolling.  She did really well.  I'm so nervous about letting these two CIO since they are so mobile.  We just put up bumpers in their cribs in case they bump their heads during the night because they move so much!!  Any advice?  TIA!!