Thanks everyone for the tips, it's really helpful.

I couldn't find 1.5mm liteply anywhere. I can get 3mm liteply here, but weight is the same as 1.5mm regular ply. A kit version is in the works, just need more time. Should be at least 150g lighter, so weight shouldn't be a problem.

A lighter motor or lighter batteries would solve my weight problem, but i have to be careful before changing them because CG will be pushed further back. CG is currently at ~30% MAC, so i have to think about that too. It's also quite expensive to make such changes.

Thanks Ed, that's a very generous offer but following the advice i got here on PM and from local pattern pilots, i already ordered a Powerbox Digiswitch today.