Can I point my apex (naked) domain to Platform.sh if I'm using Amazon Route 53 to manage DNS?

Route 53 isn’t listed here… https://docs.platform.sh/golive/steps/dns.html#dns-management-and-apex-domains

No, Route 53 doesn’t support that, except to a limited number of AWS resources, like ELBs or S3 buckets. More information on Route 53 Alias records here: https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/resource-record-sets-choosing-alias-non-alias.html