I tend to move them in the spring just before any obvious growth occurs. and yes the high temps will reduce germination. if they are in pots pop them in the fridge for a few days and see if you get any joy them.

I find it very difficult to split them at all - they are so fond of each other they hang on for grim death...
agree its probably easier without all that foliage in the spring.

I do it in autumn - the foliage by then has been cut down, leaving just stumps so you can see where they are. You can divide the clump, but you're not supposed to split up the 'strings' or chains that the corms form; the corm at the top of the string uses the others in order to form flowers. That said, I have split up the strings, especially if they're very long, otherwise you end up having to dig a really deep hole... and they seem to flower anyway.

Autumn is the best time to move the Crocosmia. Yes, high temperatures can interfere with seed germination & fruiting. Pansies are cool/cold weather plants. They go dormant over summer, so you may see germination in the fall.

thanks for info. I think will try and move when dormant in autumn so patch can be prepared for new plants. My fridge is always at 5deg C so may be too much of a shock, but will try and find cool shady place and see if delayed or cooked.

You could dump them in a big pot and cover with soil until you're ready to replant them.