GSTR 2A vs ITC claim

Hi members ,

I have an query regarding ITC claim .

Can we claim 100% ITC for bills showing as filed in GSTR 2A whereas only 20% ITC can be taken if bills showing as NOT filed in GSTR 2A as per new rule ?

I am going to take all total ITC from period April 2019 to Oct 2019 in OCT GSTR 3B .

anything should I keep in mind before claiming ITC for the above period ?