As Jim suggests, the problem with condom instructions is that these are mostly penned for the American market, for men who are assumed to be circumcised and not
have a foreskin. In such ignorance, it is therefore further assumed that a man who is intact, should be made to
look as if he is circumcised - by pulling back the foreskin - before putting on the condom.
In fact not only is there no
need to retract to put on a condom, but generally little point as during thrusting, there will be the natural penile lubrication ("pre-come") inside the condom which will allow the foreskin to find its own preferred degree of retraction or coverage anyway.
Only if the foreskin opening is so tight that the foreskin "snaps" back over the back of the glans and cannot slip forward again, will it remain in an uncomfortable position.
Other than that, any drag which results from thrusting (due to lack of vaginal lubrication) will be borne by the condom itself and only the squeezing pressure of the vagina will be felt. Since the chief complaint men have against condoms is that the latex material is uncomfortable against the penile glans, having it covered by the foreskin can actually be
more comfortable.
It is true that having the glans covered by both the foreskin and the condom or indeed, just by the foreskin during intercourse, reduces sensation but as you will note in a
previous discussion here, what appears to be
too much stimulation is a common enough complaint for young men, and the penis clearly adapts in sensitivity to however much it may be kept covered.
And generally, men whose foreskin will not retract (easily) have no difficulty whatsoever masturbating, because they do so
using the coverage of the foreskin for comfortable stroking and
if retraction to uncover the glans happens to be uncomfortable, they have automatically
learned to stroke in a fashion which avoids moving the foreskin to this extent. It may then be that a young lady who attempts to do this for them causes some problem as she has to
learn to do so with the same degree of care - but that is almost universally the case for women anyway.