"I am a new owner of an xlt .."... Congratulations! Now the fun begins.
".. and was wondering, if i pick a preset program like jewlery and coins,if i reject certain items and make diffrent adjustments can i save it even tho it was a preset program?"... Yes, you can. Actually, you can save it two ways.
If you use a factory preset program and, while experiments, you make a change or two, or three or more, then turn the detector 'Off,' then the next time you turn the XLT 'On,' simply pull the trigger toggle BEFORE it goes thru the start-up ♪♫♪♫ musical stuff and gives you the battery check and start-up info. That will quickly recall your last-used program.
If, however, you let it go through the start-up then it automatically restarts in the last used factory program.
My suggestion is to do the following. There are four (4) 'custom program' slots. Honestly, I see no real need for more than one or two programs with an XLT. For example, the first custom program slot I might load a desired program whereby the XLT is 'Hot!' Then a second program that is a little less sensitive, should one or two minor adjustments not bring the primary (1st custom program) into stable operation. Maybe a third for some specialized coil use or specialized site needs. The 4th 'custom program' position I like to label 'Test'. Then, if I am tinkering with various adjustments to one of my programs or a factory program, I can just SAVE it there to recall anytime I want.
So, until you arrive at the conclusion that all the fiddle farting with a lot of the adjustment functions is a pain in the butt and can definitely hamper good in-the-field performance (thereby settling on 1 or 2 custom programs), I suggest you simply SAVE any changes you make to the last custom program slot. Then, if you let it go thru all the start-up or remove the batteries, or just plain forget something, it will be there.
".. and will an option come up if i want to reject certain things?"... An "option?" You mean like, will the XLT ask you if you want to accept or reject something? Nope.
However, you can monitor where certain types of similar targets tend to 'read' on the VDI scale based upon the search coil used, the ground environment you're hunting in, and the program you have set up. Then, if you find that there is one certain range of numbers where ONLY undesirable targets read out in, and NO good, desired targets ever read out in, then you can reject that bank of numbers.
Just remember this: