> adjuvent [sic] is not neccesary[sic] for immune response,
Completely false. Unless the immune system has been exposed to something similar before (e.g. SARS/MERS n.b. made up example I have no idea if the spikes of SARS or MERS are molecularly similar enough), no adjuvant means situation normal for the immune system. If there is nothing to signal to the immune system that this new antigen is bad then it will treat it as neutral suppressing any vaccine response, which is worse that if the vaccine had not been delivered at all.
>is nessecary[sic] for spreading out the antigen producing character among more doses
the point of booster shots is to ensure that antibodies are maintained at sufficient levels to fight off a real infection. If a response has been established, i guess adjuvants are not as necessary? (did biomed, but not a vaccine researcher) I have no idea if they are included or not for boosters.
> rather than using a concentration of mRNA that in itself produces enough protien[sic] to induce immune response
A high concentration won't do shit if the immune system doesn't have anything to activate it, it will just see a high concentration of irrelevant new, i.e. foreign protein.