maybe start with an adjustable setup:

• rent a cheap vm, i got one for 1€/month (for the first year,cancel monthly) from ovh currently
• setup 3 openvpn instances to redirect all routes through the tunnel, one with ipv4 only, one with ipv6 only and one with both
• setup the client on your mobile phone and your laptop both with all three vpns to choose from
• have the option to choose now and try out ipv6, standalone or dualstack depending on what vpn you switch on
• use this setup to blame services that don't support ipv6 yet or maybe are broken with dualstack 🤣
• rise from under-the-stone (disabling ipv6 only) to in-sunlight (to a well-above-industry-standart-level !!! "quick" new network technologies adopting "genious") 🤣
• improve your openvpn setup from above to be reachable "by" ipv6 too if you haven't done it from the beginning, done: reach the pro-level of the-late-adopter-noob-group

(if you want, ask for config snippets)

btw i prefer to wait for ipv8😁 before "demanding" ipv6 from services i use 🤣