I've made 2 batches so far of WE Piesporter. The remaining elderflowers will sink to the bottom once the wine is degassed. The finings won't cause the flowers to settle. It's the CO2 that is keeping them afloat. My second batch is at the 25 day after start of fermentation point and as of yesterday almost all of the flowers and seeds have settled. I'll give it another week and add the F-Pack, stablizer and fining, let it sit another month and bottle it.
If you are pushed for time, put a fine mesh bag around your racking cane and you should be ok. I always use an extended schedule when making kits now that I have built up to about 300 bottles in the rack.
I'll have to remember to get a fine mess bag before I make this again and put the flowers in it to make it easier.
By the way, this Piesporter is very good at the 3 month mark! Be sure to wait a month after bottling.
Good luck!
Dave