I think 4 mice in a row (on the same feeding) is not a problem since mice are not that big .. although feeding him too often can be an issue..
If you are going to be feeding him a big meal like that .. i would give him a good 7 ot 14 day interval between each feeding. If you say he has been going to the washroom everyday than obviously that is not what you are doing .. I strongly advise against feeding him very frequently .. the main problem is that you are putting undigested food (the mice just eaten) in his stomach with partially digested food .. An sanke in the wild does not always have a full stomach ..
What kinda outcome can this have on a snake .. hmm .. I'm not sure excacly but I am sure someone else in these forums will be able to answer that. I can garantee you its not a good thing though
Just my opinion
1.3 Coastals 6.6 Jungles
3.4 West Papuan 1.0 Bred'ls
1.1 Yellow condas 0.1 Sebea
**looking for female Bredl's python**