Firstly, I'd get it out of the pot and into the ground asap. If you can't go that repot it into a bigger container. You say you've fed it but it is very small for its age. The soil in the pot has weeds and moss and looks exhausted. It really doesn't look like a shrub that has 'done well'. The distortion of the leaves looks like the work of some kind of sap sucking insect pest.

define well fed ... ken

Hmm - yeh - I suppose on reflection perhaps the feeding regimen has been woefully incorrect as I've just been adding it into my bonsai feeding one, but can appreciate that obviously there's a wealth of difference between the 2. So in answer to your question Ken -it's been on a fortnightly alternating Green Dream (Kaizen Bonsai) & Seaweed feed and in saying it had done well, I suppose I mean more in amount of growth rather than perhaps health in general. It is usually "bug sprayed" with Bayer spray monthly.

It was originally potted 2 years ago into Miracle Gro compost & is certainly due a repot BUT one of the primary reasons I bought this was with the intention of trying to downsize it to bonsai. I'm got rather bad hand arthritis so really am unable to manage repotting shrubs into larger pots & have already downsized 90% of my previous 7 shrubs (maples, honeysuckle, Spirea etc). And the weeds & moss are only there from pure laziness on my part to not do a bit of good housekeeping.

So having said all that - what feed would be best for it at this point & if it might still have some sort of bugs attacking it, any recommendation on better products to use perhaps?

Thanks so much for your help - truly appreciated. :)

It's a pity you can't repot or transplant to the ground because that is really what it needs. There isn't a simple solution. It really can't be 'fed' back to health. Looking after plants in pots is a lot more work than in the ground, and bonsai is even more labour intensive with constant pruning of tops and roots and regular repotting. If you could only get it into the ground your Cercis would be completely maintenance free. No need to do anything to it all. Could you get someone to help?

Hmm - that's sort of what I was beginning to think myself i.e. that it's not really ever going to be a bonsai candidate so I might just put it on Freegle or something & let someone else enjoy what I was hoping to see but haven't in the 2 years of growing it, namely those amazing early flowers (presumably because of the wrong feeding). So yes, I'll work to pass it on to someone with a garden asap before it degenerates past all hope of recovery. Truly appreciate your help guys - just sorry I didn't stop to check out its care better before getting it. I'm just obsessed with flowering bonsai & at times let flowers dictate what shrubs/trees I got rather than whether they'd work as bonsai to begin with! Lesson learnt :(