Multiple storage-definitions, generating archive tapes

Now that I understand a bit better how to use 2 storage-definitions I'd 
like to improve a setup at a customer.

Back then I tried to use amvault, but didn't get the concepts right 
(reading the old threads I see that I didn't even get the 
command-options right ...).

What is set up right now:

2 configs "daily" and "weekly", sharing the disklist

daily does incrementals and fulls, as usual, excludes some (huge) DLEs 
we don't want to be dumped on weekdays

weekly does FULLs only, taking >20 hrs of tape time to write 4 LTO6 
tapes each weekend

So the 2 configs each read the full data into separate holding disks etc 
-> redundancy, stress for hardware, etc

The "weekly" tapes get marked as "no-reuse" every few months and each 
year and stored elsewhere. That is important ... long term archive.

-

Now I think of integrating the two configs by using 2 
storage-definitions in one amanda.conf

by doing so it should be possible to collect the FULLs during the week 
somehow ... avoiding the huge run on the weekend etc

Does anyone do it like that?
Any hints or tips?

Things to think of:

1) I would have to "split" a physical tape change into 2 logical changers:

12 tapes for "daily" runs (= storage 1)
12 tapes for "full-only" runs (= storage 2)

(How) would amanda handle that? As there is only one tape drive it would 
have to keep everything in the holding disk and write it 2 times 
sequentially to each tape(set).

(I currently have ~3 TB holding disk, and around 10TB = 4 tapes data 
volume to handle)

2) I'd like to use a minimum of tapes for "weekly": amanda should 
collect FULLs along the way (in the holdingdisk) until a weekly tape 
could be filled completely

Maybe I would have to adjust my amdump-cronjobs: only use storage1 in 
normal runs, use storage2 for another time slot.

I think you all get the picture: I see the possibilities but don't get 
the combination right yet ;-)

Looking forward to any feedback, Stefan