Truly do not know. Or at least with respect to quantifying a response. Too many factors involved.
If the overall load is much less than 340 watts then probably not.
Fans are for cooling and if the PSU gets hot then the fan will be needed again.
However, with respect to DIY, I would just leave the fan there. Get everything working.
Then remove the fan just to test out the concept.
If a problem develops (hopefully nothing fatal to your audio gear) then put the fan back.