Does asset location impact portfolio allocations?

I was running some projections and certain situations had me converting to Roth and I wasn’t able to hit my 80/20 equity allocation because I had bonds turned off in the Roth, only 401k. So that got me thinking, is there any correlation/SORR risk data on someone who is 80/20 100% in a 401k, paying ordinary income taxes in retirement, vs 100% Roth maybe at 90/10 but not paying any taxes? Basically does a Roth allow for a more aggressive equity allocation because you are drawing less than someone in a 401k?