The basic golden rule of thumb (pardon the pun

) is if it causes no strain, pain or discomfort then it should be OK to use OFPF.
I've been following my own advice while exercising:
No pain (
not too much/not too long), no gain.
On the other hand (again pardon the pun) sometimes playing a certain way may not cause any problems now, but with prolonged use, it could be a problem further down the road. Personally, I'd prefer to err on the side of caution and use 1,2,4 on frets 1-5.
Here is a clip that is worth checking out.
I've checked your video link.
I've been playing scales/modes in the key of C major using different fingering:
(
If you are not sure, don't try it at home - it could "damage"(?) your left hand.)
Ionian:
C-D-E = 8-10-12 frets on E string (1 2 4 - left hand fingers)
F-G-A = 8-10-12 frets on A string (1 2 4 )
B-
C-D = 9-10-12 frets on D string (1 2 4 )
E-F-G = 9-10-12 frets on G string (1 2 4 )
Aeolian:
A-B-C = 5-7-8 frets on E string (1 3 4 )
D-E-F = 5-7-8 frets on A string (1 3 4 )
G-
A-H = 5-7-9 frets on D string (1 2 4 )
C-D-E = 5-7-9 frets on G string (1 2 4 )
Mixolydian:
G-A-B = 3-5-7 frets on E string (1 2 4 )
C-D-E = 3-5-7 frets on A string (1 2 4 )
F-
G-A = 3-5-7 on D string (1 2 4 )
B-C-D = 4-5-7 on G string (1 2 4 )
Lydian:
F-G-A = 1-3-5 ( 1 2 4 )
B-C-D = 2-3-5 (1 2 4 )
E-
F-G = 2-3-5 (1 2 4 )
A-B-C = 2-4-5 (1 3 4)
And so on, up and down the fretboard.
As you know all 4 open strings -
E A D G - are natural notes : C-
D-E-F-
G-A-B
My motto is "Befriend your open strings".
Variation No1:
Play E (open E string) and
hammer-on C-D-E on E string (use the same fingering from the above exercise),
Play A (open A string) and hammer-on F-G-A on A string,
Play D (open D string) and hammer-on B-C-D on D string,
Play G (open G string) and hammer-on E-F-G on G string.
Repeat the same ex. by playing
"revised" Aeolian:
Play E (open E string) and hammer-on A-B-C on E string,
Play A (open A string) and hammer-on D-E-F on A string,
etc...
Up and down the fretboard playing
"revised" modes in the key of C major.
My fingers allow me to play the following exercises (just for the sake of exercises):
E = 7 fret on A string (1st finger) = with my right-hand thumb;
A = 7 fret on D string (1st finger) = with my index finger;
B = 9 fret on D string (2nd finger)= with my middle finger;
C = 10 fret on D string (3rd finger) = with my ring finger;
G = 12 fret on G string (4th finger) = with my pinky;
P.S. Sorry for such a blurred picture. One day I will learn how to post better pictures.