This is how we know for a fact that Elon's participation in DOGE was just to repay himself for his investment in electing Donald, by killing agencies with regulatory authority or investigations into his companies, and awarding himself contracts, and trying to screw his competitors. 1/
Once he did that (I think his words were something like, "if Donald isn't elected, we will both go to jail"... I am sure beyond that Elon won't mind more tax cuts, but his primary motivation seems to be keeping his scam companies afloat... Somehow, he lost control of EV/Green Energy policy... 2/
And if his companies crash, his tax cut won't be worth that trade off, which is why he is now out campaigning against the current budget bill.
to finish my thought from above... Once Elon used the cover of DOGE to kill agencies with direct oversight over his companies, and attempted to replace companies like Verizon with Starlink (for the FAA, and others), etc... He was out, suddenly he didn't care about finding "waste, fraud and abuse"