get or put or sync files by nested wildcards

[RomanValov]

Say I have following directory structure on my S3 bucket:

/
  dir1/
    subdir/
      <lot-of-files>
    main.conf
    test.conf
  dir2/
    subdir/
      <lot-of-files>
    main.conf
    test.conf
  dir3/
    subdir/
      <lot-of-files>
    main.conf
    test.conf

Now I want to download only those *.conf files, edit them and upload back without interfering with <lot-of-files> in denoted subdirs. I can get file list using s4cmd ls:

$ s4cmd ls s3://<bucket>/*/*.conf
2019-02-23 02:01   0 s3://<bucket>/dir1/
2019-04-04 17:42 525 s3://<bucket>/dir1/main.conf
2019-04-04 17:42 755 s3://<bucket>/dir1/test.conf
2019-04-04 17:42 525 s3://<bucket>/dir2/test.conf
2019-04-04 17:42 755 s3://<bucket>/dir2/main.conf
2019-02-26 04:06   0 s3://<bucket>/dir3/
2019-04-04 17:43 525 s3://<bucket>/dir3/main.conf
2019-04-04 17:43 755 s3://<bucket>/dir2/test.conf

I dont know why, but dir2 is not shown in the output.

I've tried to download all these files using: s4cmd get, s4cmd sync and s4cmd dsync commands and their -r counterparts, but all of them either provide undesired results or produce errors:

$ # ignores directory structure
$ s4cmd get s3://<bucket>/*/*.conf .
omitting directory "s3://<bucket>/dir1/".
omitting directory "s3://<bucket>/dir3/".
s3://<bucket>/dir3/main.conf => ./main.conf
s3://<bucket>/dir2/test.conf => ./test.conf
s3://<bucket>/dir3/test.conf => ./test.conf
s3://<bucket>/dir1/main.conf => ./main.conf
s3://<bucket>/dir1/test.conf => ./test.conf
s3://<bucket>/dir2/main.conf => ./main.conf

$ # produces errors trying to get required files both to proper dirs and to sync root
$ # also produces errors denoting file names from <lot-of-files> assumed not be interfered
$ # similar results with s4cmd sync and s4cmd sync -r
$ s4cmd get -r s3://<bucket>/*/*.conf
[Runtime Failure] File already exists: ./dir1/.
Exception in thread Thread-3:ad(s)]
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
    self.run()
  File "/usr/bin/s4cmd", line 530, in run
    fail('[Runtime Failure] ', exc_info=e)
  File "/usr/bin/s4cmd", line 192, in fail
    clean_tempfiles()
  File "/usr/bin/s4cmd", line 218, in clean_tempfiles
    for fn in TEMP_FILES:
RuntimeError: Set changed size during iteration

s3://<bucket>/dir2/main.conf => ./main.conf
s3://<bucket>/dir1/test.conf => ./dir1/test.conf
s3://<bucket>/dir2/test.conf => ./test.conf
s3://<bucket>/dir1/test.conf => ./test.conf
[Runtime Failure] Download Failure: , Source: s3://<bucket>/dir1/subdir/.
s3://<bucket>/dir1/main.conf => ./dir1/mainconf
s3://<bucket>/dir1/main.conf => ./main.conf
[Runtime Failure] File already exists: ./test.conf
[Runtime Failure] File already exists: ./main.conf
s3://<bucket>/dir3/test.conf => ./dir3/test.conf
[Runtime Failure] File already exists: ./dir3/.
s3://<bucket>/dir3/subdir/ => ./dir3/subdir
Exception in thread Thread-11:ad(s)]
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
    self.run()
  File "/usr/bin/s4cmd", line 530, in run
    fail('[Runtime Failure] ', exc_info=e)
  File "/usr/bin/s4cmd", line 192, in fail
    clean_tempfiles()
  File "/usr/bin/s4cmd", line 220, in clean_tempfiles
    os.unlink(fn)
OSError: [Errno 2] No such file or directory: './dir3/subdir-m4iyx9a5s3zbnlq.tmp'

s3://<bucket>/dir3/main.conf => ./dir3/main.conf
[OSError] 2: No such file or directory
[OSError] 2: No such file or directory
[Thread Failure] [Errno 2] No such file or directory: './dir1/subdir/<one-of-lot-of-files>-mufsq9gd640jr71.tmp'

$ # produces errors and doesnt do anything sensible either with or without -r flag
$ s4cmd dsync s3://<bucket>/*/*.conf
Runtime Failure] The obj "*/*.conf/../../dir3" does not exists.
[Runtime Failure] The obj "*/*.conf/../../dir3/main.conf" does not exists.
[Runtime Failure] The obj "*/*.conf/../../dir3/test.conf" does not exists.
[Runtime Failure] The obj "*/*.conf/../../dir2/main.conf" does not exists.
[Runtime Failure] The obj "*/*.conf/../../dir2/test.conf" does not exists.
[Runtime Failure] The obj "*/*.conf/../../dir1" does not exists.
[Runtime Failure] The obj "*/*.conf/../../dir1/main.conf" does not exists.
[Runtime Failure] The obj "*/*.conf/../../dir1/test.conf" does not exists.
[Thread Failure] The obj "*/*.conf/../../dir1/test.conf" does not exists.