Hi, less of a question more of a findings
from searching the questions (which i did myself before) generators and multiplus comes up often
I build generators, i am less "techy" than many with victron products but have used 1500 rpm japanese diesels with 4 pole windings for over 25 years on ouback and trace
without a doubt victron (mines a multiplus II 5000/48) are the pickiest inverters with a generator that i have encountered
for some time now ive been fine tuning a 1500 rpm kubota D905 (895cc) with meccalte 4 pole AVR regulation,
multis like to spit out their dummies, say what you will, they do
some usefull pointers re japanese 1500 rpm generators and multis
7kva+ continuous rating for a 3000va, 10kva+ continuous rating for a 5000va
kubota use a centrifugal governer which reacts too slowly for the victron, so when operating at say 50% load capacity of the generator continuous output running load and charger and say a freezer motor kicks in it is often the case that the multi will spit its dummy, leading to the relay chatter as the multi spits out, then re connects until the next "coincidence", such "coincidences" often seem random to the end user
careful tuning of input amps and enforced (quite prolonged) generator warm ups can help with hassle free running
if i could do it again id go yanmar 3tne 78a (1200cc) with a continuous rating of 12kva 230 single phase, with "in pump" governing is better than the kubota "in engine" governing, i ran one to 15,000 hours on a trace and it never missed a beat
initially gross oversizing seems illogical and overly wastefull of fuel, but in hindsight shorter runs at higher charge capacity woud make sense and lead for a more stress free life
i hope some find this usefull as it was a subject i researched much before resolving, the victron generator faq page is quite good, but re 1500rpm diesels the above is better, i used to re-build Gardner engines, like i say, less techy on victron but slow speed diesels i know my ting