Chile plants, leaf curl, compost too 'hot'?..

Hi again folks!

I have a bunch of capsicum plants, mostly superhot Chinensis vars but there's also a pair woody stemmed candelabra style Fillius Blue in there, and a trio of Spanish sweet red peppers (Dulce De Espana) - 15 plants in all, and also a pair of small fruit tomatoes, all in a little poly-cube lash-up, and all in pots.

Everything's looking happy (can't upload an image though it seems) with a few peppers already growing on the 'Espana, and TONS of little purple fruits on the Fillius, also a few tomato fruits on the tom plants too.

They are all in the same soil mix which consists of some garden soil, some spent organic compost, some fresh organic compost, some fibrous plant matter and a load of worm-bin compost.

Each plant has recently been potted up, bio-inoculants added (Plant Magic Plus 'Granules') as per usual. These were all late starts after a big accident with the first round I sprouted, so biggest pots are only about 5 litres or so, with most of the superhots being a few sizes down from that.

All were rooted out before re-potting each time, and are busy rooting out their new pots now.

Problem I have is the smaller of the plants/all the hottest of the superhots, have leaf curl on the younger leaves especially - this is a rigid curling, with no wilt or change of shade that looks just like examples of Calcium deficiency in capsicum, but it is absent from the other chiles and peppers and the tomatoes?

Could this perhaps be due to overfeeding with the worm poo, rather than them being short of calcium? I do know that nutrients can get 'locked out' for want of a better term, by overfeeding - just can't see this being an actual calcium deficiency at all.

Only other option I can think of is heat stress, and I know it's gotten hot in there (into the 40s C in the airspace, but no higher than about 25C in the root zone), but the superhot vars. are supposed to be good with this, and the toms and other capsicums haven't even *winced* at that...

Cheers for any input folks ',;~}~

Shaun.

Edited to add - I run a fairly deep wet/dry cycle with productive, relatively quick rooting potted plants like peppers and tomatoes leaving them until the pots are really light but the plants not wilted, then give them a big flush of fresh water until I see a reasonable %age of runoff, so they are never stood in excess water which I know can cause similar looking issues, but they are never either allowed to dry out and wilt.

Also wanted to add I considered thrip and aphid, but then a) only a few are effected and they are all in a 1 x 1m or so footprint together under polysheet, and the other plants are fairing fine, and although there does appear to be some insect leaf damage, it seems minor and the culprits not evident...