Sounds like there is more risk, or as much risk, in a redesign than there is keeping them as is.
What is the background, are you planning a voyage in the Southern Ocean, or Gulf Cruising?
Brand new rigging can fail. Sure, there is a correlation with very old rigging failing, but that doesn't exclude new gear failing. Especially if it is a novel or un-proven design. Or poorly installed.
An alternative design is to glass in a large lump of hardwood. You could then screw the chainplates straight to that, keeping them visible, so you meet your objective for inspection etc. This is w