What are my options for this kid?

So nannykid is 4.5y, 32-35lb (not totally sure, guessing 34ish) and 40" tall. I turned him FF at 4y1m, and he asked to turn back around shortly thereafter. He's happier RF, I'm happier with him RF (for a variety of reasons,) I'd like to keep him RF. I have a perfectly lovely ProSport in the garage - in all honesty, what he really wants is to RF in the ProSport lol - if I opt to FF him. But both of us would prefer RF.

Right now he's in a NextFit, and we're running into the headrest issue. Chicco has okayed continuing RFing use but as he creeps up the headrest it's making me more and more uncomfortable... particularly for a kid who does not need to RF. We got the NF because the Radian was not a good fit for him. I have a MR and a Scenera, too, but I'm guessing he's too tall. Haven't checked.

What are my options to keep this kid RF? I'm not opposed to buying a new seat (several of mine expire next year) but I'm not looking to spring for a Foonf or even a Fllo. I'd kind of prefer low profile. Things I'm considering:

1) Try him in the Radian again and see if it's a better fit now that he's grown. Baby sis is using it now but she can go back to her MR.

2) Buy a CA and violate the 40" rule, which I feel okay with for personal use up to a certain point. He's short-torsoed.

3) Try a Graco clone again. I had one when they first came out, but I hated the buckle and didn't love the short seat pan.

Is there something new and fabulous I've missed? Can't see the advantage to the 4Ever since I won't use most of the modes.

Any other ideas for us?

How about a Britax clicktight convertible? It looks like the Marathon has higher RF height limits than the current G4 convertibles, and the Boulevard and Advocate even more so. It looks like you'd have to wait about a month to get it, though (Amazon lists the release date as October 6).

A Sureride?

SureRide has the 40" height limit too, right? If I'm ignoring it anyways, I think I'd go with the CA for low profile.

Britax convertibles might be an option. Wonder how they are with leg room? I had an RA50 and got rid of it, too hard to buckle up with folded legs there lol. Waiting's not really an issue, if the seat is right, though it is kinda pricey. Hmm.

If you wait for the CLICKTIGHTs to come out you can get advocate pricing through Britax on some models. I was told those should be added to the program in November. It's roughly 40% off MSRP.

Ooh, good point! I *do* love the ClickTight.

My concern is still the legroom - not for transport, but ease of buckling. Honestly I'm leaning towards getting a CA, but I want to go to BRU and try it in my car first. Just trying to figure out if there is an option that doesn't involve violating a standing height limit.

(If it was my kid, I'd buy the MT a friend just finished with, I think it would be absolutely perfect for our needs, but I'm not comfortable using an import for someone else's kid lol.)