I have, but unfortunately theyre all 'all-or-nothing'. Id like to keep maybe 25% of the encounters,
0% just feels stupid. But ill keep looking.
Thanks for that very detailed answer, unfortunately its all too complex for me. But once i know what im doing, ill get back to that.
For now my solution will just have to be 'Option 2', im currently playing on a snes classic,
not using retro arch, so im gonna have to sort that out first, but not untill i have completed terranigma and smrpg.
All or nothing is one thing. However if cheats enabled is a key, and cheats disabled is another key then you can automate that easily enough. Don't know about on a SNES classic but on a PC having a script poke usually one of the F keys, waiting 4 seconds poking the other F key it needs to do the opposite, waiting 12 seconds (75% of the time off or on or whatever) and repeats until stopped is trivial -- it might even be the example project for any scripting program you care to use. Also if you have any kind of muscle memory for something like saving a work in progress then it can be doable by yourself as well if there is a button combo.
Skip the exp stuff for now then. By the time you have done the other things then it should be within range.
If you can do the thing where you want infinite ammo so you start a search, fire a bullet, search for anything that changed (or maybe decreased), fire a bullet, search... maybe don't fire a bullet and search for anything that remained the same, fire a bullet... to get infinite ammo you can do this.
My general approach would be get the item that allows it. Assuming I don't want to give myself infinite items and fumble with the menus chug a potion every however many seconds/steps then you get to find a flag in memory.
As firing a bullet/using mana/using an item/jumping in a pit to die/gaining score/... is easy and has a quick reset time until you can try again a lot of the time it can be quicker to source then than flags but flags are still doable.
If you can wait around and it tells you something wore off then then do that. If it is going to be next 5 minutes/500 tiles then that gets more tedious (though the turbo button can help with this).
In that case I would probably mess around with savestates. Take one before you glug a potion* or use an equip (more on equips shortly), start the search, use a potion, see what changed, wait a second or two, see what remains the same (might not work if it is a straight timer with no straight flag but worth trying anyway), wait a bit, see what remains the same, possibly restore a save, see what changed, don't use a potion yet but see what stayed the same, use a potion, repeat until you have a manageable list of things to watch.
If it is an equip and you don't want to waste a slot then they can be done much the same way. I will note some games only apply the flag when you press OK or even get back into the game/out of the menu. To that end cycling between two things in a menu might not gain you much so to play it safe, or maybe just if the "simpler" option does not work at first then start in the game and get back into the game before doing the search.
*if it is a late game item and you don't have a save or savetate to play with to find it them item cheats can usually be twisted. Just life infinite ammo if you can buy say loads of the boring and basic potion/starting dagger/... you can find infinite of those. Most items will then be either a slightly different location (byte 1 of this table is potion count, byte 2 is bigger potion, byte 3 is full potion you only get in the late game....), or have a item code attached to the number of them in your inventory (think how you might do a spreadsheet or table in a text graph, except rather than text in most old games you have a number).
On EXP then multipliers are nice but if you fancy making a code you might be able to set baseline EXP to something else just like an infinite life cheat (search, do a battle and gain some EXP, search again, do a battle, search, maybe do nothing and then search for anything that remained the same... if you have a quick to defeat enemy** that won't take consumable items that is worth say 1 exp then even better). Worst case there is some games might get a bit confused if you set the EXP over the next level cap so in that case make sure you set it 1 below and then next exp gain/battle it will sort it for you.
You have to cycle out cheats as you want but if you keep a note of what things are doing what you can still do the battles but gain the same effective end result/power levelling. Most codes you find on cheat websites will be max exp/near as makes no difference max exp but that is great as most cheat codes are of the form "type of cheat they are, location in memory of this, data to put there" so you just change the data to put there from max/ridiculous value to not a lot. Go one more if you want and have a button activator to say add 1000 to it.
**nothing wrong with giving yourself infinite life, nice late game equips or super stats to speed this up/make life easier.