I would be fully in favor of sticking with Jackson at LT and using our 1st round pick on a different position, unless our scouts think we are getting a decade-long elite fixture at LT, like a Pace or a Whitworth, in which case, I think you have to take him, and then shift Jackson inside. Otherwise, don't fix what is not broken. O-line can wait until round 2 or 3.
A young, well above average LT on a dirty cheap contract is almost as valuable as a talented young QB on his rookie contract when it comes to roster construction.
LT is a position of the utmost importance so it is unsurprisingly very expensive to retain a good one. Just look at what the Rams paid Noteboom (kill me now... I hated that contract the moment it was signed). The o-line drives everything on offense. But in particular, you need to protect your QB's blind-side. Especially if you have a QB like Matthew Stafford - older, injury prone, not very mobile, tons of miles on him.
Alaric Jackson has held up very well against some very good defensive fronts lately (Cleveland, Baltimore, and New Orleans). And generally has been pretty good all season. He is young and still improving. He has proven he can excel in this NFL blocking scheme, which is never a guarantee when transitioning from college, and has been building chemistry with his linemates as they continue to gel.
I said it at the start of the year, even when I was expecting a middling season, and have repeated it multiple times since then throughout the campaign - this is a young o-line, so as the season wears on, and their NFL experience and chemistry build, I think they can become a very good unit that sneakily performs as one of the better units in the league. That seems to be happening now. I rate our o-line top third when healthy, and look for them to possibly take another step forward next year.
Even the depth is getting much better. I do quite like Noteboom as a versatile 1st man off the bench when injuries strike that can play multiple positions along the o-line... just not at his price-tag.