The stalks have elongated. Would you cut them to replant at ground level? These types keep leaves through winter.
Yes, you can prune off the flower.
Here is a link with more information.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/lewisia/growing-lewisia-bitterroot.htm
I grow from seed lots of lewisias, but the only one that won’t germinate is tweedii lemon. Am I doing something wrong? please help
The seeds of Tweedia should be fairly easy to germinate; they do need bottom heat though.
Heat the bottom of the nursery tray with a warming mat set to 70 degrees Fahrenheit if you are germinating the seeds indoors where temperatures are typically cooler. Leave it at 70 F at all times during the germination process.
I hope this helps your germination of this particular variety. Also verify the quality of the seed you have. If you are successfully germinating other types; perhaps it's worth talking with the company you purchased the seed from.