Summoners Savant

You are exceptionally adept at summoning monsters, with the ability to call upon and control more powerful beings than normal. You gain the following benefits:

Whenever you cast a spell which summons creatures, the maximum CR of the creatures you can summon increases by a total of two (one creature by two, two by one, four by one forth, etc).

When you cast a summoning spell that requires concentration, with a duration of up to 1 hour, you can eliminate the need for concentration and change the duration to an 1 hour. You can only have this ability active for one spell at a time.