If one player gets his 30d VIP and then buy another 30d SVIP (unlikely but they may)
He has VIP&SVIP in the next 30days.
Could you please add a command to lock the expire time?
I think it may request much code work, but its useful..

Why not simply add 30 days to the VIP when SVIP gets bought.

@BrainStone That's a fix, I will try it
It would be complex when there are VIP、SVIP、MVP、MVP+ ...
But still a good idea, thanks

This is beyond the scope of what should be reasonably provided by LuckPerms.

Temporary permissions have a fixed expiry time - counters, timers, measurements in terms of play time, etc etc become too complex for reasonable functionality within a permissions plugin.

You may find this option useful.

https://github.com/lucko/LuckPerms/wiki/Configuration#temporary-add-behaviour