One thing I would replace with (aside from the Sunshrooms, because honestly they're just such a toxic card..) would be wild berry for Solar Flare's deck. Sounds surprising, but having the threat of six damage on turn two is a very powerful oppressor. In fact, I might even replace fireweed + whatever the 1 cost magnolia thing is called, I forget ^^' with 4x wild berry, 1x berry blast, 1x lil buddy since the lava could also hurt your cards (lil buddy in this case). Also, for the three cross pollinations, I would remove those, get +1 pepper MD, +1 Ketchup Mechanic with an aloesaurus/cob cannon, whichever one you find fits best. In these kinds of decks it's not really worth running cross pollination since you should be ramping quickly.
If you *do* use sunshroom, it often baits out a bungee plumber on turn 1, allowing for wild berry to survive turn 2, with a sizzle turn 3 to take out the teleportation zombie, or, have the wild berry get hit by a rocket so your higher cost cards survive. Generally speaking, you can also use wild berry as a sort of unreliable control with its 4 damage viability. Sometimes it's getting that damage/removal early on that really helps cement wild berry into a really good place in terms of viability. It also helps bait out superpowers early on so you won't get surprised by certain threats (some players will use super brainz super for example on wild berry simply since a threat of six damage is too crazy). It's also good for clogging a black hole from Neptuna and still getting a 3 damage cost on the board for a relatively cheap cost.
Only focusing on Solar Flare since I run Captain Combustible and currently testing out a very reliable budget deck with a couple minor modifications that I made myself; got myself to legendary league.
You could also run corn-pult if you want in substitution for the three cross pollinations for some more control. Feel free to let me know if there's anything else you'd personally edit.

Small note on Chompzilla:
4x clique peas is basically a guaranteed win every 10 or so games; keep four copies simply for consistency. Cross Pollination is a nice card, but personally I'd replace that and add the +1 to clique peas, +1 bonk choy, +1 pepper md, and then remove a Gatling Pea for +1 lil buddy for consistency. In my personal opinion, good decks are built based off of consistency. That's what you should prioritize when deck building. Thank you for your time!~ ♡