According to https://bugzilla.redhat.com/show_bug.cgi?id=1836198#c39
I test on gcp with 4.5.0-0.nightly-2020-07-23-201307
300 volume mounted in about 6 minutes without failure.
Fri 24 Jul 2020 07:25:07 PM CST: pod running:279, expect:300
Fri 24 Jul 2020 07:25:26 PM CST: pod running:283, expect:300
Fri 24 Jul 2020 07:25:52 PM CST: pod running:293, expect:300
Fri 24 Jul 2020 07:26:12 PM CST: pod running:300, expect:300
INFO: All 300 pods are running.
5 minutes and 43 seconds elapsed.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHBA-2020:3028