2.5 weeks later there's been a few changes.
First thing you'll notice is the tannins leeching out of one of the pieces of driftwood. It's actually cleared a bit now, but still leeching a little. As for the plants:
HT is growing very well, if very tall. I'm slowly trimming bits and replanting it in the FG. 2/3 crypts melted, but both of those have come back with new growth. A number of the older NL Java leaves have started to go bad, so I've removed a couple of them, but left others. On the bright side, there's growth of existing leaves, and quite a bit of new growth coming through. Anubias also seem quite happy. Rotala is perhaps the least happy of the lot; growth is slow, but it is growing.
Had some issues with the solenoid malfunctioning, but Adam from AquaScape Design provided me with some very helpful advice so it's now all sorted. Diffuser is now gunked up so the Co2 output is reduced; need to buy some bleach to clean it up.
When I initially set up the Eheim 2217, I neglected to install the quick-release things. This resulted in two problems, the first being that I obviously couldn't use them to disconnect the filter easily, and secondly I was unable to use them to reduce the flow, and the flow was quite a problem. I've now got the quick-release thing on the outflow at least and I've been able to adjust the flow to a much more reasonable rate.
And the final bit of news: the tank has now fully cycled is now the home of 10 seemingly happy celestial pearl danios. I was hoping for some Corydoras hastatus to start, but I was unable to locate them. Having said that, I'm loving the CPD so it's worked out well so far.