{{{{{{{{hugs}}}}}} it sounds like naps are crazy right now.....
At 6.5 mos, most bubs are doing 2.75 - 3 hrs, so my guess is that he does need a longer A time. It looks like you've been trying a bunch of different options with A time and I'm wondering if you just need to stick with one for a few days and see if it begins to sort out his day. Is his first A time of the day often his shortest? If so, I'd start there - maybe start with 2.75 hrs of A time for at least 3 days and see what happens. If he naps longer than 1 hr, keep the same A time before his next nap. If he naps less than 45 min, shorten up the next A time a bit so he doesn't get OT. If the 2nd nap is short too, offer the catnap. Most bubs give up the catnap between 6-8 mos, so offering it some days and not on others is perfectly normal at his age.
Have you started solids yet? I'm wondering if that factors into anything too.....
hang in there!!
michelle