The problem I see with incinerating chloride salts, gold chlorides are volatile (yellow fumes), and silver chloride can also evolve in fumes as white smoke.
Because of this I always, wash the chloride salts in a solution of sodium hydroxide, neutralizing acidic powders, and rinse the NaCl salts (salt water) that forms, with plenty of hot water washes, my thinking here is that I will help to make oxides of silver and base metals and remove most of the chlorides in these powders, that I feel would otherwise cause me a loss of values in fumes in the incineration process.
Rinsing of the salt NaCl is also important because gold can be volatile if incinerated with NaCl (table salt).
(If lead as chlorides are involved in the powders they are to be washed out in boiling hot water (before I would have neutralize the chloride powders prior to roasting them).
Lead chloride is insoluble in cold water but it is pretty soluble in boiling hot water, silver chloride is insoluble in both cold or hot water (although the silver chloride takes time to settle in solution, and also if solution is being stirred by the boiling action the silver would be stirred up and not settle, so keeping the water hot to keep lead chloride soluble and also letting the silver settle and giving the silver time to settle is needed to separate these two metals, (or lead from the other chloride salts).
The incineration will drive off the acid portion that formed the metal salt; (incineration drives off this acid portion from the salt as a gas of that acid),
Example copper metal dissolved in HCl/H2O2 gives a salt of copper, in solution Copper II Chloride (Cu2Cl), or as insoluble powders as white Copper I Chloride (CuCl), If we incinerated the copper chloride red hot we would drive off the chlorides as a gas, and also convert the copper to copper oxide, as we expose these copper powders to air or oxygen, it is important to crush the powders and clumps, and stir the powders to get good exposure to oxygen, I am not exactly sure at what temperature all of the chlorides would convert to oxides But I do know it would be very close to red hot.
Sulfate would need red hot and held at that temperature for a period of time almost an hour, as you need greater than 700 degrees before the sulfate salts even begin to break down to sulfur dioxide gases.
Also incineration helps to oxidize most of the metals, this makes it easier to dissolve the metals into solution later, and metals like tin will be much more easily removed in steps later, this also greatly reduces your chances of loosing gold in the tin laden solutions, makes filtering solution less of a major pain in the backside (tin after incineration is remove with boiling hot HCl and hot water rinses), (if you made a chloride metal salt from using HCL, incinerating before using nitric will keep you from dissolving gold when you do not want to, the chloride salts and HNO3 would form aqua regia if the chloride salts were not incinerated to metal oxides (removing chlorides), before using nitric acid.
Do you see the similarity to the SSN leach? (Where saturated salt NaCl and nitric acid form aqua regia, and will dissolve gold)
Understanding why and when to incinerate is very important to success in recovery and refining, Harold has done a great Job of helping me to understand this, ore and electronic scrap the incineration method is extremely important tool, and it can be a major difference in getting values or loosing your values.
Edited to add this thought:
I would Incinerate the pins again you could have traces of lead and tin salts (chlorides), that you did not, (or cannot) rinse out.
Note: a metal and an acid will make a neutral salt, rinsing off acids and testing pH to see that these salts are neutral does not remove these salts, and the neutral tin chloride salts can again be a problem when you add nitric to the pins (if you do not incinerate them again), the tin chloride can make aqua regia, the tin make a gel in nitric (hard to filter), and carry tin through the solution to the later stages of processing, basically making you loose values.
Tin in a chloride solution of dissolved gold forms stannous chloride in this solution, this reduces the gold (to colloids of gold they will not settle), and since the colloids of gold in solution are already reduced to metal (that will not settle), a stannous test will not show you a positive test of this gold metal held in solution, making throwing out your gold into the waste stream a costly mistake, easily avoidable with a quick use of the torch now.