Well FF 16mm 82 front is gonna be a challenge
VND is a double glass filter and quite thick - Id guess you need to be onsize not stepdown.
Overall ND is a world of sh*t - whatever way you go round it it is a royal PITA
Basically I got went from my FS100 to the F3 just to get ND filters - Now Im prepping to a job on the black magic and back to the horror of ND.
Pick a filter size and step up to it - thats what Ive done - 77mm
I have tiffen VND too - £500 down the pan unless green is your thing.
The BMC job we have 2 solid B+W 3 stops and 2 solid B+W 6 stops enabling me to shoot while the A/C preps the next lens.
In reality Ill stick to two lenses 35-70 and 18 to cut filter fandangle.
Coots has/had a Lee clip on system 100mm that I actually found very impressive.As for my 96mm front nikkor 50-300 4.5 - well I just made a pigs ear out of a fan cover..