Neither LotW nor eQSL handle operating from multiple locations gracefully(*). LotW’s approach is a bit clunky, but not too hard to work with, but eQSL’s approach (if you try to do everything correctly) is, frankly, bonkers.
Once I’ve put my log into something from which I can export an ADIF, uploading to LotW isn’t all that complicated, though each activation has to go in by itself as LotW requires a single location to be associated with all the QSOs in an upload. I may need to create a new location if the summit’s not one I’ve already got in my location list in TQSL. I do my best to put all my QSOs (with the exception of my very occasional /M ones) into LotW as accurately as I can.
To do eQSL to the same degree of accuracy I first have to create an associated account for each activation. This contains the location and start and end dates and times. Once they are created I can upload the QSOs for all the activations in a single upload (assuming they’re all under the same callsign). I’ve a lot of sympathy with folks who keep just one account per callsign (with a nominal but inexact location) and put the real location specifics into the comment field (or just refer to the SOTA database (see Answering CQ SOTA Twice - #43 by EA2IF for an example), because the “one account per location and time window” business results in hideous numbers of accounts. I expect I have not uploaded all my activations into eQSL, though I think most of them are there.
(*) It would be so, so, so much easier if they’d both just make proper use of ADIF fields like MY_GRIDSQUARE, MY_STATE, MY_IOTA, and even MY_SOTA_REF, and dispense with the clunky location handling, but they don’t, and there’s no obvious sign that they ever will, so I guess we’re stuck with the clunkiness…