To be honest if you love the tone of the amp when it's boosted by the tube screamer but, hate the tap dance you might consider something like the Voodoo Labs GCX audio switcher or RJM switcher. These units let you press one button and bring multiple pedals in/out of the signal path at the same time. I also believe with the GCX and the RJM you can set it up so you can perform amp channel switching. (I'm not 100% sure on this but, it should be pretty easy to research) The good thing about the switcher resolution is you would know 100% what the amp is going to sound like. (No worries about getting the amp back after it was modified and not liking the sound) I believe the switcher units might be a little more expensive then the mods you are thinking about but, the upside is if it doesn't work out you can always sell the unit and get your money back. (I always try to by used in good condition to retain as much value as I can) You don't really have that option with a mod. Also with the amp staying stock you'll have a larger re-sell market if you decide one day to sell it. (I know now everyone says I'll NEVER sell it but, G.A.S. can get pretty bad some times) I would think it would be harder to sell the modded amp because less people want a modified Mesa then a stock Mesa. Also everyone I've seen who sells a modified Mesa never gets the money back they put into the amp plus the modification. These are just my .02. Good luck on the tone quest.