Manual gearboxes: how long till "warmed-up"?

[Gavc]

If yours is difficult until warm and you know this drive around it(1-3). I have improved mine since I 1st bought my 308gt4 more than 24 yrs ago. Major benefit was Redline 75W-90 transmission oil and I also re bushed the linkage and also re aligned the selectors which is sump off and adjustments underneath. Please dont attempt if not competent and without the aid of a proper ramp and assistance. The boxes do have some engineering tolerances which can be improved and I have driven one which we great shifting cold. I had a long conversation many years ago with a well respected Ferrari specialist who was also Phil Hill and John Surtees mechanic in F1. He told me that when he supported club racing they used to use automatic transmission fluid in the 308 series to help with shift quality. Though this was for racing, like everything be sympathetic and dont abuse.
For reference its usually around 5-10 miles before things start to warm up