Can beams be up against a post base like this?
There is nothing wrong with this from an architectural standpoint.   Honestly you should only have tied in framework touching the support posts.   Meaning here - if the footing heaves, the ledger is failing no matter what.   Either it adjusts because of the tie or the concrete, result is the same.

It would be against standards (and maybe code) to have non-tied framing laying on or within a micro-distance of the support posts.  

Being practical though, this is poor design.   At least give yourself some wiggle room.   I would say 2" at least.   What if one of your pours doesn't set right, what if your measurements were slightly off level, whatever.   I wouldn't want to have to shave concrete out to make the ledgers level.   

So my answer is in theory fine, but not practical.  Also it sounds like you are a DIYer and haven't built 40 decks.   Don't make things so hard on yourself.