Mix ratio

If the mold feels stiff and hard enough to make a pour then I say go for it.....dirty little secret, I always add more hardener to my mold mix...usually 2 or 3 grams at the most.
The larger the mold , the least likely you are to find enough fault with it to not use it...now if it where a small mold, you might find some issues, but keep in mind what I said if the mold still looks good after you have pulled the buck or master. Personally I like using a mold that is a little bit stiffer (HS-2) so when I apply pressure to a multipart mold, there is no distortion that could ruin the resin pour.
If you do find an area that is suspect, you can cut that area out and re pour the RTV Silicone as it will bond to itself so long as any type of mold release has NOT been used.