...and a few minutes after posting, I discovered this:

https://github.com/dbuezas/lgt8fx

Arduino Hardware Support Package for LGT8F's

Adding this URL to your board manager, you get a properly working platform where the SoftwareSerial baud rates are as they should, and you even get to choose the clock frequency, from 1 MHz_all the way up to 32 MHz, twice as fast as a genuine ATMEGA328P. I'm starting to like these boards now!

Hi there! This thread is very old by now -- I am posting for the benefit of others who find the thread the same way I did.

If you multiply the baud rate by 0.75 as you initialize SoftwareSerial, it works fine!

For example, if you want 9600 baud,:

//9600 baud on wavgat R3
SoftwareSerial.begin(9600 * 0.75);

I believe something is off with the CPU frequency of the WAVGAT UNO R3 clone boards. It seems to be 1.33x faster than the F_CPU value defined in the header files.

I discovered this by manually testing different interim baud rates until I found the absolute end limits where my 9600 baud data was getting only slightly garbled, found 6790 / 7610 to be the pain points, thus 7200 is right in between, which is equal to 9600 * 0.75.

Hope this helps someone.