I bought those adapters to connect my old Firewire HDDs. The Firewire drives worked perfectly and I could also boot from them. But occasionally and very randomly the LG UltraFine 4K 23.7" Thunderbolt display went black for a few seconds, sometimes a few times during a few minutes which was very annoying. Sometimes me or somebody else just moving nearby (without moving the desk or the cables) seemed to trigger the error and I suspect automatical display brightness might have played a role there.
Those two adapters were clumsy so I decided to move forward and bought OWC Drive Dock USB-C Dual Drive Bay Solution, USB 3.1 Gen 2 (OWCTCDRVDCK) which works perfectly. With the new OWC Thunderbolt drive dock there are no more screen blackouts. Maybe the extra Thunderbolt adapters caused them?
I also very briefly tried my old D8 (essentially the same as miniDV except it uses Hi8 tapes instead miniDV tapes) Sony TRV320E (unnEUtered to allow analog-in and analog-to-DV passthrough so I could use it to digitize all old VHS footage as well) and it worked quite OK in Mojave although occasionally I had to reconnect the cable to make it work. I have an old Mac mini late 2009 and also PowerBook G4 2004 for officially supported DV work but I have essentially retired the DV gear by now.
As I said, newer hardware and macOS might be flaky with DV camcorders. AFAIR some Monterey (?) point version did not support DV import, for example. So success is not guaranteed.
Other folks have used QuickTime Player for the import.
I used the old iMovie in Mojave: iLife 06 installer doesn't run on OS X 10.7 or later because it is a PowerPC application. iMovie HD 6.0 can be installed via Pacifist ($20): Open the iLife 06.mpkg installer with Pacifist, select the whole iMovie package and let Pacifist install all components to their correct places. iMovie HD 6.0.2 Combo Update and iMovie HD 6.0.3 Update can the be installed normally. iDVD 6.0.4 doesn't run on OS X 10.8. OS X 10.9 is the last where iMovie HD 6.0.3 officially runs, or in macOS 10.10-10.14: Right click to show package contents. Open contents. Open info.plist in Text Editor. Scroll down close to the bottom and locate line:
<key>CFBundleVersion</key>
<string>6.0.3<string>
Change the 6.0.3 to 6.0.5.