Hello Michael!

All is OK with V4!!!

I have generated a 350 megapixel image (with export AI) with a final resolution of : 24694x14174

The operation took about 12.3 Gb ram!!
(My config i7-7700K nvidia gtx 1080 Ti 32Gb Ram 3000 Mhz Windos 10 Pro 64bit)

All is OK!

I have used this 3dm scene : http://take.ms/0wS6q

Ciao!