An F/O on the 737-400 told me of his experience of being PNF during a take off where the crosswind component was around 15 knots. The captain (from the old school of captains from a particular former Australian legacy airline) pre-set almost half control wheel deflection at the start of the take off roll and held that deflection for the whole take off run.
Within around 10 knots of V1 the acceleration appeared to slow markedly
Especially with pilots 'impressions', you have to be very cautious. In a max weight 747-200 take-off from a hot and sultry BOM, I was very concerned how close the end of the RW at the V1 call it was so close. I reported that the performance was incorrect and no way could we have stopped with an engine out and on 3 reverses. The airline Performance analysis team re-examined it and concluded that there was still 100m or so in hand. i didn't believe it for a moment. A week or so after getting their response, exactly that happened, the same service lost and engine at V1, same conditions, rejected on 2 reverses (1 locked out) and still stopped with....100m in hand.
I'm afraid an F/Os assessment of acceleration during TO is just not reliable. The human body can feel good acceleration, but as for sensing degrees of graduated power acceleration, it doesn't even start. Wind effects can do funny things to the ASI as well and make it appear acceleration has stopped. I do believe partial spoiler on one side around 120kts really has no effect, but that's not what Boeing says. But- having half control wheel deflection in a strong crosswind (over 20-25kts) is a good idea. All the surprises I ever saw on lift off were from not enough, not too much. On 747 and 737, we practically used to work on about 1 division on the boss/5kts, with the knowledge when you lifted off, you would need more immediately after the wheels lift off. So question- is it better to have more close to VR than get airborne and have to go to 90 degrees as I have seen frequently and near full deflection is applied to control the wing drop? You might not believe it, but it happens- watch carefully next time the other pilot does a strong crosswind takeoff.