He is using WAV files, so MP3Gain is not an option here. Also as Burrrn uses WaveGain which has auto-clipping prevention enabled by default, then clipping will not occure by using Burrrn.
EAC is still actively developed by Andre Wiethoff, but there generally goes some time between every release, as he has a full time job and codes EAC in his free time only. The latest version is v0.95b4 from 21.02.06. If wanting a ripper that checks for errors i.e. secure ripping and also rips albums as images with cuesheets and have all index numbers and metadata stored in the cuesheets like CD-TEXT,ISRC and UPC codes, then EAC is the only app for doing that job. It’s main strength is that it’s very advanced and features a wealth of options for tweaking the ripping process.
Anyway, in the main Burrrn window then you just select options and then under the ReplayGain tab, there are options for tweaking the RG adjustments done by WaveGain. I would personally recommend sticking to the standard reference i.e. 89dB, but it’s off course up to you. In the main Burrrn window under Pre-processing/ReplayGain, then you can select Album Adjustment/Track Adjustment. If you leave the RG settings in the options dialog alone i.e. to 0dB, and select either Album Adjustment or Track Adjustment in the main Burrrn window, then the album will be scaled to 89dB. Then if e.g. setting the RG options under the ReplayGain tab to +3dB under Album Adjustment and also enable Album Adjustment in the main Burrrn window under Pre-processing/ReplayGain, then the album will be scaled to 92dB. The difference between Album Gain and Track Gain is that Album Gain will scale the albums average volume to 89dB, while keeping the volume variations intact from song to song(some songs are quit and some loud on an album). This means that all tracks of the album will be scaled by the same dB value. Track Gain means that the album will be scaled to 89dB, but will not keep the volume variations intact and all songs will be made exactly the same i.e. 89dB. This means that the songs will not be scaled by the same dB value, but e.g. one song be scaled by -1dB and another by -2.5dB etc. It is logical to use Album Gain for full albums and to use Track Gain for tracks that come from different albums like compilations. Also you cannot select to only process some tracks of an album by WaveGain in Burrrn, but only either all tracks or none of them.